Can't blame? Give me a break. I'd have fought better than that bloody piece of shit, and I have practically no melee training aside from the little the military training gave. And this guy is supposed to have trained for years at Yuuno's home, and furthermore has that strange blade inside his arm. He lost purposefully.

He wanted to lose. Don't ask me why, but since we saw in the flashback he wanted to die during the terrorist attack, I guess he still has a death wish lingering somewhere in the back of his mind, and he seeks excuses to escape life by failing to perform his duty.

If he had shown some wits during this show I'd give him some leeway by considering this could be a clever, if cruel, plot to reach a final solution somehow, but since Shinkuro is a cowardly loser, I think I can safely discount such an idea, although it could still proceed according to Benika's master plan, whatever that might be.