J4 Ultimate Damage Timing and Tower Executions

Scenario:

J4 vs Ryze top. Ryze chases J4 under J4's tower. Jarvan ults Ryze, trapping him under the tower, but dies mid-flight before landing.

Ryze (who does not have Flash or another escape, obviously) is executed by the tower a moment after the walls fall, so the time period of J4 ultimate (3.5s) to Ryze dying was 4s to 4.5s. J4 had not dealt any damage in the past 15-20s or so to Ryze besides the ultimate. When Ryze dies, J4 doesn't get the kill. Instead, Ryze is executed by the tower.

Either A) this is not a bug, in that the terrain formed, trapping Ryze, but the ultimate did not do any damage because J4 died a split-second later while still in air, and this is the intended way for the ultimate to function; or

B) assuming Jarvan did deal damage, this is a bug, in that when Ryze died to turret shots, the game didn't "see" Jarvan's ultimate's damage and therefore did not reward him with the kill; or

C) this is a bug because Ryze took zero damage from the ultimate, when the damage should have hit at the same time the walls formed; or

D) this is a bug because the damage should have hit Ryze whether Jarvan is alive to finish the animation or not.

If I had a replay, I could go back and look to see whether Ryze actually took the damage or not, which would rule out several options, but unfortunately, I don't think the software I'm trying to use (League Replays) is functional at all.

Also, if I did deal the damage, I'm assuming the 4s or so from when I ulted Ryze to when he died from tower shots is not long enough to remove him from battle in terms of me getting a kill or the tower executing. If that is the case, then wow, when did that timer get so short, and nevermind all of the above.

Thank you!

(Edited for clarity)