This is absolutely a bug, but I think it’s associated with mounts. I get it on PlayStation, so I’m fairly certain it’s not just confined to one platform. It has nothing to do with the purge. He just had bad timing when it occurred. Not sure exactly how it happens, but if you have a mount, it’s an easy fix. When this happens, just get on your mount and try to use a healing item. After it says you can’t use it, get off the mount and it should work again. Hope that helps for next time.