Again with the misconception that Accelerator is all powerful... obviously he could work something out if he had time to think and wasn't being punched in the face every 2 seconds but under this situation is perfectly believably for him to derp around while facing an enemy who's immune to auto reflect.

It's like when you're playing a videogame and you always use that same move because it's awesome and powerful and kills everything, until you face an enemy immune to it. Yeah you'll beat him after a quick reload but in that first battle he's probably gonna slap you around pretty hard.

If you want to bitch, bitch about how Touma manages to get up after being thrown off what looked like 20-30 meters up. Plot armor has always been around though so it's silly to start complaining about it now.