Because that's referring to him being able to react to her own attacks in time.Someone’s not reading
^ Needed to develop a surefire move just for stopping Gungnir to be able to stop it
Touma needed no such thing against any of the Calamities and wasn’t breaking fingers nulling them or their attacks
Try again, clown
The thing repeatedly emphasized throughout the volume that he can only do because of his "experience" (which isn't how experience in combat works but I digress).
"Even with a special power in his right hand, he would be smashed to pieces before he could use it."
That quote specifically says that the issue is not being able to negate it, but being able to react in time.
Genuinely what are you talking about?