This isn't the first time Bob's been a guest in someone else's brain. But before it was with someone he knew and trusted. Ironhide is still, to him, an almost-total stranger, and Bob is acutely aware that the Autobot could delete or rewrite him with a thought. He can, perhaps, be forgiven for being a little nervous.

"I'll tell you what I can. There's a lot of stuff I don't know for sure, though."