We had a similar discussion to this a while ago in one of the pleasant threads that discussed police shootings prior to the police-specific thread came into being. At the time, the NYPD officers on the scene shot something like 96 times combined and only 10 or 11 shots hit their target while the remaining rounds were recovered from various nearby objects.
During that discussion, the remarks for bad marksmanship came about, as would be expected when you see only around 11% of the shots hit their mark. So I did some digging on that back then - some two or three years ago now - and found that NYPD's officers do very well in their target ranges, well over 50% (I want to say close to 90%) of their shots hit their targets. In the field, the average drops down to roughly 6%. It's a completely different situation, and like you said, that variation of "buck fever" hits and making your shots count is a much harder thing to do even for trained professionals.
People can do their own research to verify the information. It was simple enough to do at the time, but I'm at work now.