yes ugh foggy would hate seeing matt like this, being treated like he's stupid/an animal, when foggy knows how intelligent he is, and honestly how deeply he feels everything - like he must know that there are a million things going on in matt's head, and none of them are good. so he probably would intervene, because, uh, it actually took foggy a while to persuade matt not to keep everything bottled up - to actually let foggy hear that he's enjoying something rather than biting back every sound, and foggy doesn't want the doctor to send them spiralling back to square one on that.

but maybe also he recognises at this stage that matt is just digging himself holes, and when it gets like this at home foggy usually ties him up or makes him wear noise cancelling headphones - things that'll limit his options and ground him, so he doesn't have to think so much. so...although he corrects the doctor, saying they won't need to take a gag home, maybe he agrees that matt could use one for the rest of their session.