dropping ball after tag

[Steve M]

JWalker,
Two things to consider. Was the contact flagrant or malicious? If so, that's an out and likely an ejection. If it was not, then decide if the catcher voluntarily released her grip on the ball. If so, that's an out. If the release was not voluntary - as in trying to reach into the glove to remove the ball - runner is safe as along as the plate/base is touched.

Steve M