First, Riftwing had managed to avoid the enemy's attack FIVE times in a row, which is absolutely lucky considering the small speed advantage (except its natural flying buff).
Monsters with the flying ability can often avoid being hit by non-flying monsters.
Yes! I have read about the flying ability as well. It gives a 25% chance of avoiding the attack. Still, if Riftwing did not avoid taking damage at least 3 times, I would have lost :D