Bernie Sanders seems to be going along with the "we won the Latino vote" narrative. Ignorance or dishonesty?
Frankly, there's a reasonable chance he did. It's likelier that it was Clinton, but not impossible it was Sanders. Anyway, with only an exit poll to refer to, it's fair game for him to say this. Clinton would do the same, as would any other sane (or insane) politician.
If Clinton won all the majority Hispanic precincts, then she certainly won the Latino vote. Also, there was no exit poll, just an entrance poll, which are worthless.