Sounds like a classic case of target fixation and panic mid corner. This is the process: you feel a corner tighten up, and suddnely your brain tells you that you are going too fast, and the bike will slide out if you dont do something - you wont make it. So your first reaction is to pull the front brake hard (which stands the bike up straight) then you look right in front of you (hoping to avoid what you are going to hit) Your arms freeze up fighting each other, you lock up the rear wheel and you go straight off the road.
I did this many years ago, and managed to ride it out. It is a scary feeling, and your only conlcusion since you dont understand motorcycle dynamics is that "the bike wouldnt make the turn." If you are lucky, you walk away.
Of course, we all know that the likelyhood is that you could have made the corner easily if you simply countersteered it all the way through and looked thru the turn. Even washing some speed of with controlled braking helps, if you know how the bike will respond.
Now, after some good training and experience, going into a corner a little too hot is really a non issue. You know what to do and how to override your fear response.