I have absolutely no clue WHERE the ezreal was when he shot it, nor do i know what angle, or anything, the only thing i do know is i got hit by a trueshot barrage that was straight up invisible.

I was right next to a friend who also did not see the trueshot barrage (and unlike me he did not die from it, i was lux mid)

Sadly i do not have much more to state on the matter, wish i had more helpful information, But fact is we cannot have invisible ezreal ultis.
That **** ain't fair.

I could see the ulti multiple times later on, but if he shot more invisible ones, i wouldn't really be able to call them out....because.....they're fukken INVISIBLE.
Still i did SEE SOME. but i got killed by one that made me rather mad, since i was already being dominated. struck up my 16th loss in mid across all my accounts in 2 years play, the invisible ulti, didn't help my mood all that much, neither did the enemy teams 14 year old shaco.

/rant
TLR Invisible Ezreal ultis, we need to look into this.

Were you in your base when it happened? I have noticed a bug where Ez ultis will fly underneath the ground of the bases where you can't see them very well sometimes, but still cause damage above. It's like the ground is raised to an altitude above that on which the ulti flies -- I guess the ulti can't fly over the stairs at the entrance... haha I haven't seen it in a while though, but I also don't play Ez much.

Nope i was in mid lane next to my tower, No ****ing clue where EZ was. could of been in our jungle, bot lane, mid, dunno.
I was laning vs a brand, ez was supposed to be bot but i couldn't see his icon on map at the time, playing lux so i had map awareness, his icon wasn't there. last i saw he was in their jungle.
Wards in blind games, because lux lazers.

Yeah it is a bug with some shots fired from the brush. If he was in a bush and your team did not have vision of him when he fired, sometimes you don't see them at all. Same with nid spears, Draven ults, etc. Riot made a note of it in the last patch and they are working on it I guess. But yeah man. it happens.