If you witness behaviour like this, you should "Flag for moderator" at once.
It is a bug, but it is not a very common one, because (if I recall correctly) only the 10k users have the ability to see the deletion votes. (I may be wrong, please correct)
So, this means that it is only something that can be exploited by the already trusted users, and there are lots of way that they could abuse their powers. This is just one of them.
I think it's an interesting bug, but wouldn't necessarily be worth putting extra dev time into, because as noted, the 10k users already have other powers they could exploit if they intend to be malicious.