Kha'zix ultimate upgrade bug (Gameplay)

I turned level 16 as Kha'zix in a game I recently played. I had evolved my Q (single target ability) and my E (leap), and was going to go evolve my W (skillshot). When I looked down, I noticed all 4 of my evolvolutions were available as an option. I decided to click my E to find out what would happen, and it accepted it as an upgrade. I have not tried to replicate this glitch and I thankfully did not lose my game because of it :). I checked just to be sure but my W (skill shot) and my R (ult) were not upgraded gameplay wise. Thank you for looking at my report. It's a minor issue but something that could hurt if you are trying to evolve in a pinch situation