For crissake the OP is long gone.
The *real* issue is that the OP doesn't trust her BF. He clearly doesn't know how to communicate in a way that she finds reassuring. And yes, a good partner does take some responsibility in communicating this way. Maybe its his issue, maybe its hers (insecurity). But this single issue is trivial.
Now, if it turns out he is the kind of guy that won't say shit with a mouth full of it (and they do exist), be it issues big or small, then she will have to decide if this is the guy for her. I think that is what she is worried about, longterm. Right now tho, its time for her to let this go.
You can all lead by example, btw. Let this small issue go. Quit overanalyzing.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh