I have used up all my votes a few times while /Reviewing close votes. A couple of times (that I've noticed, maybe it happens every time), when I've used my last vote to close while reviewing, that review hasn't been counted.
It happened again today, and I took some screen shots to verify this bug.
With 2 votes remaining, I've reviewed 26 questions, and here are my recent reviews:
I review one more question and it shows up in the list of recent reviews:
But after I use my last vote, I get this message:
And the last question that I reviewed doesn't show up. (Don't think an image is necessary, I can add one if needed.) After using those 2 close votes on reviews, my review count has only gone up by one: