Negative finesse?

On some piece drops the finesse count decreases, which sounds like something that shouldn't happen.

Steps to reproduce:
1. Set ARR to a nonzero value (e.g. 1).
2. Hold left in 40L mode.
3. Without letting go, hard drop a bunch of pieces.
4. The finesse counter will decrease by 1 or 2 for every piece that's dropped, resulting in something like -13 if you top out doing this.