Leash knot remains if ridden entity causes lead to break

The bug

If a rideable entity is leashed to a fence, and you ride away, the lead drops as expected, but the leashknot remains on the fence.

How to reproduce

1. Lead a tamed rideable entity to a fence.
2. Ride away from the fence until the lead breaks.
   → Lead drops
   → Leash knot remains on the fence