Hypothetical Scenario, if I had a LotR Tyrion (response: Kneel a clansman to save Tyrion), and a standing Timmett (Knelt Clansmen cannot be killed), and someone flipped Valar, if I kneel Timmett to save Tyrion, would Timmet survive?

I'd argue that Timmett survives, because he was knelt in stage 2 of the action resolution (to save Tyrion), and therefore cannot be killed during stage 3 (Action is executed). I'd just like to clarify if this was actually the case. Thanks!

Was anyone arguing the other direction?

Since the word "cannot" is absolute, it is not over-ridden when the kill effect is resolved just because it wasn't applicable when the kill effect was initiated. The timing is a little strange with the save, but so long as the character is "cannot be" at resolution, it takes precedence.