[It's an easy reflex when he sees his jaw tighten like that to slip her hand into his for a gentle squeeze. While he's saying that it was a while back, he's obviously still upset about it, and that warrants at least a mildly sympathetic response.

She manages a slightly lopsided, sad smile.]

I'm sorry too. I shouldn't be complaining about a soured relationship, when at least he's -- you know, alive.

[Paralyzed from a stray bullet ricocheted by his former best friend, but -- details.]

What was he like, your mentor?

[She'd read somewhere that talking about the person helped bring back positive association with them instead of sadness.]