Sorry, Chris, I don't really agree with you on this one and think you guys are over-reading things.
He could've just meant that he sent his offer to take the item at the asking price. In other words, he should've said "I will take it. E-mail sent" or something like that.
"Offer submitted", in and of itself doesn't really mean shit, does it? Maybe his offer was "I'll take it." Maybe it wasn't. No way to really tell for sure just looking at what he wrote.
In a sense, "I'll take it" is just an offer, right? We all understand that once you say "I'll take it", you need to live up to that.......but it's still just an offer until the seller accepts. So he said "I'll take it" and submitted his offer to take the item--no big deal.
Then again, maybe the guy did offer an "I'll take it" and then try to negotiate.....which, of course, would be douchebaggery. But you can't necessarily tell from what he wrote.