[gameplay] kalista rebind disables sentinel (W) passive

When playing kalista, if you bind the wrong ally with your passive and then purchase a new black spear and rebind, sentinel's passive will no longer work for the new souldbound. The visual mark will appear above the target's head indicating that kalista marked it, but the soulbound can neither mark nor proc the target. After rebinding, in fact, no ally can ever proc sentinel, including the first soulbound even if they are rebound.

Steps to reproduce:

1. pick kalista
2. bind an ally
3. bind a new ally
4. attack a target enemy or monster with your ally with sentinel (W) leveled expected result: target enemy/monster takes sentinel's passive proc damage actual result: target enemy/monster is marked only by kalista and takes no bonus damage

A video of the bug is included at this link: https://drive.google.com/file/d/0B_67KF__UEz0R1FoQWV0cEM5NjA/view?usp=sharing The first minute and a half show the bug occurring as described - the rest of the video shows experiments with rebinding previous souldbounds to try to get sentinel's passive to go off at all, showing that rebinding once disables it entirely.

reproduction rate: 100%

Thanks for reading, and credit to kiwi13103 for identifying the bug in the first place.