So, Raf's diagnosis is paranoid personality disorder, which is characterized by severe mistrust towards others driven by paranoid thinking. In Raf's case, he genuinely mistrusts the notion that anyone actually loves him or cares about him as a human being, and that people go only through the motions of pretending they do in order to exploit him; fear of being abused is implicit.
He spends a looot a lot of time and emotional energy trying to determine what specific people want from him--initially so that he could interact with them in the 'safest' way possible. Sometimes that meant telling them flat-out that he will not do/provide the thing he suspects is the other person's goal (with the intention of making them leave him alone), or (if it's someone who's company he likes) he'd deliberately attempt to give the impression that there's a chance they'll get what they want out of him--for as long as he is able to until the 'inevitable' falling out. His inherent mistrust and desire to avoid getting himself hurt meant that while he had a lot of nice acquaintances, he had basically no actual friends.
Raf generally, to anyone acquainted with him, just comes off as a very aloof, quiet, and private person with a busy personal life that everyone else is simply on the outside of. He goes out of his way to preform kindness to anyone he interacts with, regardless of the situation, because relentless amiability was always conditioned into him as a core trait of his curated persona growing up, and--yanno--it's worked very well for him. But also because--he doesn't fall onto the default belief that all people are bad and unworthy of kindness. "No one actually loves me" hadn't become synonymous with "everyone is a bad person". It just meant that "everyone will eventually be bad to me if given enough time".
This was his unchallenged reality from late teenagehood until some several months(maybe even a year or so?) after he had graduated from university and moved in with his uncle. His uncle recognized that Raf was very skittish, anxious, distrustful and prone to 'jumping to the worst possible conclusion' about certain things--which would often lend to some very tense interactions. His uncle, however, chalked this up to Raf having grown up under the thumb of an extremely manipulative, emotionally neglectful, exploitative mother. The situations where Uncle Bill would have to calmly and patiently prove to Raf that he wasn't gaslighting him over his wildly inaccurate assumptions/interpretations had become a more and more common as their relationship otherwise grew more and more warmly familial.
Things came to heads after the realization dawned on Raf that his uncle intended on using him as the ticket to win his mother's endearment. If Bill could successfully deliver Raf back into his mother's grip, that would easily be currency enough to convince her to reinstate Bill as a core member of Ephrem Records--thereby ending his uncomfortable estrangement with the family. And Raf would be back to living his life as his mother's preforming puppet; no autonomy, no control over his own life, no rest, an absolute nightmare.
Raf had grown too comfortable and complacent--his uncle had given him literally everything, from a place to stay, to a job that treated him well, to all the space, peace, and quiet he wanted, and with absolutely no obligation. Raf didn't have to work, he didn't have to pay rent, he didn't have to do anything he didn't want to do--uncle Bill had been willing to accommodate it all. Uncle Bill had once 'admitted' to Raf that 'guilt' was a factor motivating his charitable kindness. It hadn't quite sat right with Raf at the time--and now he knew why.
And, when it was made plainly obvious to Bill that Raf wasn't sticking around just to be hand delivered back to Monaco, Uncle Bill continued the charade, offering to provide Raf the car and cash he'd need to move as far away as he wanted to be. And--it wasn't until the morning after his first full day of driving across boarder into the states, on his intended route to Mexico, that Raf got into the car, sat there...and remembered that his grandmother, the largest financial owner of Ephrem Records, had been trying to entice his Uncle back to Monaco, back into the family--non stop--for years. Bill could go back literally any fucking time he wanted to, with or without Raf. And, Bill hated his mother--or so he was consistent in suggesting as much. Why would he want to endear himself to her in a manner that played to the traits he disliked about her?
Raf called up his uncle, tried to make head and tails of things over a long conversation over the phone, and--upon...not quite having enough shamelessness to straight up ask if going back to his place in Vancouver was ok, his uncle offered Raf the option to return--on the sole condition that he'll accept psychiatric help. With hesitation, Raf agreed to it.
Raf would consider bolting again a handful more times over the next few years, and each time, the 'situation' would pass with no horrible consequence for stubbornly electing to 'wait and see'/, or 'resigning himself', instead of repeating his mistake from the first time. It left Raf feeling more and more convinced that he cannot trust his own perception. Between this and therapy, Raf became pretty adept at not saying/doing anything that would be acting upon his suspicions/fears until he's had time to dissect the situation and get a second opinion from a designated person of trust--specifically, his uncle.
Basically, for better or worse, Raf has decided not to trust his own reality when it comes to his own (specifically negative) understanding/'interpretations' of his relationships and interactions with others, and has instead elected to replace it with whatever his uncle's is (a position of trust that Magritte eventually inherits). Raf figures his life is basically in his uncle's hands anyways--considering he's convinced himself not to leave Vancouver (he -did- move out into his own apartment, however) and has repeatedly resigned himself to being "cashed in” for whatever personal gain his uncle might be gunning towards with him.
AND SO, to finally answer your question ahaha: when Raf outwardly vouches against someone's character with as much straightforwardly committed plainness as "If you hire that guy, I will quit", that guy has committed a transgression that is awful beyond any reasonable doubt.
This is also why, as Raf and Magritte became more and more friendly over the course of their weekly jam sessions, Raf suddenly going chilly and quiet on her was a recurring problem she began encountering with more frequency.
At the core of his instincts Raf will always, beyond conscious thought, believe that people can only see him as an exploitable resource and will, without fail, harm him accordingly. But--there's now a layer of increasingly thick vellum that's been laid overtop of that core--a contradicting truth that's been asserted to him, that he is being asked to put more stock into and to internalize. He slips up, there are many many times where he doesn’t catch himself on time, or is feeling too strongly to employ meaningful countermeasures. When a situation aligns in a manner that allows his paranoid thoughts to really sinks its teeth into him, he can still have catastrophically ugly, fear-driven moments...but he's been working really, really hard to manage it. He wants that lightly obfuscating vellum to become so thick that it's opaque. He wants to believe that what Uncle Bill and, eventually Magritte, say is real is real. He can't trust them, but he will anyways. He has to believe that love is an action--a deliberate choice, and if love’s an action then so, too, is trust. Because regardless if they can really love him, he has decided that he really loves them.
And the reality can reward or punish him for it as it sees fit to do so. An endless frightened loneliness is worse than dying.