I'm not sure how the code is actually written, but it seems that votes are registered as soon as I click on the up/down arrow, and not when the mouse button is released.
This causes problems for me as I like to highlight text when reading it. I'll often accidentally vote something up without actually meaning to. The usual behaviour of most UIs is that if you remove your mouse from the element/button before releasing the click, then the click doesn't have any effect.
However, this is not the case on Stack Exchange sites. This is acceptable on questions and answers, as I can nullify the vote by clicking again. However on comments, it is impossible to nullify the vote.
Can this functionality be fixed, or allow an option to nullify comment votes the same as votes on questions and answers?