Gamebreaking Diana/Fizz interaction (Bugsplat)

just got through the worst game of my life. Why is this? If Fizz and Diana both proc thunderlords at the exact same time while diana is casting her W, it causes an immediate bugsplat for the Diana player. It happened 3 times in 1 game. I was using Dark Valkyrie Diana and the enemy was using Atlantean Fizz. Every time he would Q through me as I popped my W, if both thunderlords popped at the same time it would immediately bugsplat me.

Thankfully this was not a ranked game but considering Diana is my go to pick into Fizz this is a major concern if it continues to happen. It gave him first blood and he won 2 other skirmishes with me due to this.