I think it's unlikely that anything related to the EPB itself would have been damaged. The most obvious suspect for the symptoms you described would be a brake maintenance issue, particularly caliper slider pins which have become basically immobile, due to lack of lubrication. So that's the first thing that needs to be evaluated.
Next, if the brake maintenance has been properly taken care of, there's been a history of dragging calipers on that model year (including a TSB). And it might be possible that applying the EPB while driving caused that dragging condition to kick in on yours.
If it's possible for you to do so safely, you can try a rolling stop test. Drive a mile or so from a cold start, and don't apply the brakes at all. Let it come to a stop on its own, and once it's stopped you can apply the brake and put it in park. Get out and check to see if any of the brakes (especially the rear) have heated up at all.
But if you can't do that test safely where you live, then you could try jacking up the rear end and turning the wheels by hand. Apply the regular and EPB, then release them a few times to see if either or both wheels become less free to turn as a result of applying the brakes.
