I was as depressed as the next guy after the first debate. But I never believed it was because Obama was tired, uninterested, or unprepared.
I believe it was a planned and thought-out strategy. His strategy. He was ahead in the polls and didn't want to cause a stir. He didn't want to come across as the angry (black) man to feed the racists. Also, no one could have expected that Romney would do a 180 on every previous position he held during the primaries.
So, yes he may have accepted some coaching after the first debate, but I'm sure that too, was his decision and I doubt he needed to be talked into it.