[He doesn't know what went on in that temple, so for all he knows Belloq is telling the truth. At least, the part about not being able to get to Niko. He still doesn't believe Niko is dead, though. Maybe that's just because he doesn't want to believe it, but he guesses he'll find out.]

Right.

[He sounds unhappy to think of Niko in that situation.]

Well... thanks. For telling us.