What Rule Set Has The Bug?

Equal Opportunity

What is the possible bug?

**The mantoid is not using equal opporunity and instead attacks the frontline, as if it has taunt.
**

My disintigrator has 1 hp, so I would think an opportunity monster is going to attack the lowest hp monster, right? Maybe its intended to be this way, but it seems weird to me. This happens 2 times in this battle, it also did it when his cursed windeku had 5 hp but 2 monsters in the back had 4 hp. I understand that in the situation of sneak + opporunity that SNEAK TAKES PRECEDENCE and sneak monsters will continue to hit the back line, this makes sense. But when it comes to Snipe + Opportunity I don't understand why it would not execute equal opportunity if there is no mage/ranged monsters to snipe.

Maybe I am missing something? Like I said, maybe they intend for it to work this way. But then I would ask, if this was Fog of war ruleset and something has Snipe + opportunity is it going to use opportunity in that situation or just attack the frontline.

I hope this gets to the right people if I found something that needs to be fixed, and if its supposed to be this way then I look forward to understanding why! Thanks for reading!