[Master Assassin]

Which reminds me... about the projectile Mikoto used, if people still can't agree on Keroko's point.

I suspect what actually hit Touma's hand first was - the launched energy bolt that propelled the projectile, not the projectile itself. And with the energy bolt reaching Touma's right hand first, since its source is from a supernatural cause (Mikoto's power), it became cancelled because of Touma's ability.

My logic is because the coin would be somehow engulfed in the energy bolt (if it doesn't melt/get dissolved due to the high concentration of energy in the bolt) before it hits Touma. And when the energy that hits Touma first gets cancelled, there'll be no more energy to move the coin with a freaking speed that it'll hurt, its velocity will get reduced to an amount - if not zero - that'll enable it to hit Touma harmlessly.