Explosive Bubbles timing/targeting

Had a game tonight where Explosive Bubbles came out, at its initial 5 HP.  " At the end of the Environment turn, this card deals 2 Energy Damage to the X non-Environment Targets with the highest HP, where X = the current HP of this card."  The 5 highest targets were:

* Villain Character

* 3 heroes

* Villain target

One of the heroes had a 2-point retaliation attack. 

We reasoned that we got to choose which order to do damage in, since it wasn't specified.  First we damaged the 5-th highest Villain target.  Then we hit the Villain character.  Then we hit the hero with the retaliation attck.  The retaliation reduced EB to 3 HP.  We reasoned that since "the current HP of this card" was 3, and it had damaged 3 targets, that we were done.

Opinions?

That is correct handling of the card.  When X changes the effect updates, and in the case given stops as it has fulfilled its text in full.

I have a strong urge to dissagree here. Just because it's Phantaskippy. Not because he is wrong.

Huh. I wouldn't have played it that way.