Looking over the list Krookodile has only really lost one battle under Ash's ownership. That was to Skyla's Swootbat. He wasn't knocked out by Rizzo's Jellicents, just got pushed back into a cage. I don't recall him losing any battle against Pikachu while under Ash's ownership either. I think everyone is more or less accurate.
Might wanna add Excadrill knocking out Nero's Seviper to the list and Pikachu knocking out Bianco's Zangoose.