TC De-aggros on boar after one shot

I now almost exclusively shoot boar with tc when luring as I find it much easier to get a nice placement, and the feeling of the vills popping out to deliver the final volley is just Kreygasmic.

However, occasionally I garrison 6 vills in tc when the luring vill gets close, right click the boar, tc shoots once. Then it doesn't shoot again, and the boar has hit my luring vill once or twice more, so I un-garrison my other vills to shoot the boar normally, and garrison the (now almost dead) villager.

Then the tc (with one villager!) shoots the boar again and the final one arrow kills the boar.

The problem here is the tc not shooting twice, can anyone explain why this happens and how I can avoid it?

Thanks!