Inconsistency about cat sitting when cat is in minecart

Players' control of the sitting/standing configuration of a tamed cat is inconsistent when the cat is in a minecart.

How to reproduce:
1 Tame a cat
2 Make said cat sit
3 Put said cat into a minecart
4 The cat should now be in the sitting position while inside the minecart
5 You can now make the cat stand up while it's inside of the minecart by right clicking anywhere in its collision box
6 Once you have made the cat stand up, you can't make it sit back down by right clicking on its collision box