Hmmm yeah hopefully people in his program are addressing this with him. There's certainly some pressure as a resident to be able to handle things well, and people that close off and stop communicating tend to do so as a poor coping mechanism for their own shortcomings. If he didn't understand what was happening or what needed to happen therapeutically, he may have been scared to call his senior/attending and be found out. Obviously this coping mechanism backfires brutally on most everyone who uses it.
Ironically, it seems like some of the worst offenders are the most highly pedigreed and look highly accomplished on paper. They could probably get this question right on a test, but struggle in real life. They also seem to derive their identity from appearing like the smartest person in the room, so making a call because they're stuck is especially difficult for them.