Pulsefire Ezreal

I just played a game of Hexakill as Ezreal with the Pulsfire skin. While playing i had issues where if an enemy champion was shielded my spells would go through them. Two instances come to mind. I was about to kill the enemy Varus when Karma shielded him. My Mystic Shot went through Varus and hit Karma instead. Then the other time the enemy Thresh was getting away so i fired my Trueshot Barrage. It showed it going over him, But because he shielded himself it didn't hit. Everyone saw it, Thresh should have been dead but because it went through him he walked out and didn't die.