I don't see how he can really be blamed, Ash and the others hit the container and it was going to blow up, if he didn't release it then the helicopter would caught in the explosion probably wouldn't have ended well for him or the the others. Also they didn't have anything left after that, so they wouldn't have wanted to stick around and get destroyed by three angry Legendary Pokemon.I must say, Zager really isn't faring very well....in fact he could be held more responsible for TR's losses because they follow his commands to give up. He better watch himself with Giovanni...
Team Rocket being included wasn't the problem. It's how they used them in the episodes. The first part they were good but in the second part, TRio and Dr.Zager hardly got any screen time and that was a huge disappointment.This would have been better, in the end, without the Team Rocket stuff shoved into it. All they served to do was break up the flow of the action. If they weren't there, this would have been a much better conclusion.
The biggest problem though, I think, is that the art and animation quality in this episode was terrible. Tornadus, Thundurus, Landorus, Jessie, James, Meowth, Lewis... all of them looked completely off-model all the time. Considering the director for this episode was the one who directed one of the worst-looking episodes of late Sinnoh, DP175, it's not surprising.
The first part was good? Pfft. They were smirking like idiots, hiding behind rocks and whatnot. They had better actions in those filler episodes showing themTeam Rocket being included wasn't the problem. It's how they used them in the episodes. The first part they were good but in the second part, TRio and Dr.Zager hardly got any screen time and that was a huge disappointment.