Unarmed vindicators raise their arm in offensive way when attacking

The bug

When attacking, vindicators without weapons raise their arm in offensive way.

How to reproduce

1. Spawn a vindicator using the command

   /summon minecraft:vindicator ~ ~ ~ {HandItems:[{},{}]}
   

2. Go to survival
3. Let it attack you
   → Look at its arm and you should see that it is raising its arm which looks like it's performing a salute