I think you may be reading more into the original quote you posted ("I didn't know things were this bad") than is actually there, but I haven't seen the statement you're quoting in its entirety and context -- it's important to keep in mind that the press likes to drop a word here and there to make things "clearer".
If I were President and my staff told me they were recommending a $700 billion bail-out of the financial markets, I'd probably say "I didn't know things were that bad" too (emphasis added) -- although I'd probably use the alternate phrase "Holy fuck!"
It also wouldn't be unusual for a President to not know about something at all until his staff told him -- that's what the staff is for. The President of the United States, in general, doesn't spend a lot of time watching CNN or listening to the radio. He'd be notified by staff of something like this.