He’d just been attacked by a magical source that disarmed his weapons at the wrists, was cast wordlessly and without wand motions, and did not leave an obvious bolt to block. This is probably a bad time to show off.
At a deeper level, Voldemort (and Mad-Eye Moody) favor a combat philosophy of dodging, under the quite reasonable realization that there are a large number of spells that can overwhelm shields or are unblockable.
“the stunbolt leapt out of her wand and -
slowed to a stop in front of Professor Quirrell’s raised hand, rippling in midair like it was still trying to fly and making a slight hissing sound.”
Does LV really need hands to stop stunbolts? Why did he try to evade?
Resonance. He doesn’t dare involve himself with Harry’s magic in any way.
He’d just been attacked by a magical source that disarmed his weapons at the wrists, was cast wordlessly and without wand motions, and did not leave an obvious bolt to block. This is probably a bad time to show off.
At a deeper level, Voldemort (and Mad-Eye Moody) favor a combat philosophy of dodging, under the quite reasonable realization that there are a large number of spells that can overwhelm shields or are unblockable.