This question has popped up in seminars over the last several months. My answer is to put it into the transcript as "2012." I know. You are yelling, "But that is not verbatim!"
First of all, we are not verbatim all the time. When "goverment" is said, we put in "government." For "accidently," we put in "accidentally."
Second, I think we have to keep in mind that we are the only ones in the room looking at exactly HOW something is said. The person who says "212" without the zero has no clue that you are going to do something weird with that. He (or she) doesn't get the difference. He thinks he said the year.
If you put in "2'12" or "2-12" or something other than the regular year, the guy reading your transcript is going to wonder, "What the heck is this?" He doesn't realize that is the way he really said it.
So my thoughts are to just go ahead and transcribe the year -- and, yes, even if it is video-recorded.
Happy punctuating!
Margie