> This is a personal judgment. He was passive aggressive in what way?

It's an exit interview, so that is an excellent question for HR to ask.

> excluded you from the team: How was he excluded?

same as above.

> code was awful: Again, is this a sentiment shared by other members of the team or is it just one junior engineer being super opinionated about something

Something you can correlate with other feedback, and see if it gets mentioned repeatedly, or not.

...

But you straight out just always assume the most negative interpretation, and then come to the conclusion that your prejudice was confirmed, and support spreading that outside the company.