Darius ultimate under tower

Well i wasn't able to record it but i was fighting a Darius top lane to save the tower and he was on 50 hp and when he ulted me the tower shot that was suppose to hit him was negated and did no damage to him. If you are able to check recent games and watch it you will see this happened not only to me but to the aatrox that he was facing in the lane. Thanks for taking the time to read this and i hope this can get fixed soon!