I'll start with the positives from the episode - Oshawott was amusing and I liked Swanna's voice.
This is an absolutely terrible battle with no redeeming factors whatsoever. Starting with Pokemon getting knocked out on either side for nothing more than stupid tactics, Ash leaving Pignite out when Samurott came in, Kotetsu sending out Ferrothorn and Swanna out against Pignite and Pikachu respectively - completely unnecessary and hardly fitting for what is supposed to be a match up of two of the top 8 trainers in Unova.
Hydreigon highlighted Ash's lack of preparedness - against Tobias' Darkrai at least his Pokemon looked like they were trying as hard as possible and it was the sheer strength of their opponent that led to the losses - while here Boldore and to a lesser extent Oshawott did nearly no real damage or even look at any point capable of doing anything. But then Pignite turns around and knocks it out fairly easily - making Ash's other Pokemon look bad and it seem like it's not Kotetsu being strong, just Ash's Pokemon being too weak to beat it.
I'll explode if the twist at the end of the battle is a double knockout but because Ash had six out and Kotetsu only five he wins by default.