Now that I know it's not supposed to happen, this startled me when I saw it a few minutes ago. (see attached screenshot) Looks like the bug isn't fixed after all. =(
Basic rundown: I'm about to commence combat with a Grunt at point-blank range - no shots have been fired yet. I'm equipped with a single Imp Targeting Computer, I've been stationary for several turns, and my Prec Assault Rifle that is the culprit has an innate +20% accuracy bonus. Somewhat interestingly, unless the range bonus at point blank is only 2%, I believe my accuracy should be even higher than it is. I don't know if it's related, but my hit chances for my other weapons also happen to have nice, divisive-by-five results.
EDIT:
during the fight, my accuracy percentages rose slowly, consistent with enemy heat rising, including that of the Prec Assault Rifle, so there was no odd cap-at-100% going on