In my recent TMA there was a comment that I'd been docked 2 marks as I'd gone over the limit. I was sure that I hadn't. It turned out that the wordcount was done by the marker AFTER they'd added their comments in word - and so I was about 20% over the limit!
These things happen! Quite speedily I got a return email which essentially said 'Ooops, I'll put it right'.
The net effect is that I'm now at 76% on this TMA (though I haven't yet seen anything official).