[WEAPON/BOSS INTERACTION] Specifically the War Javelin and the final boss

[Casel002]

So, first off, SPOILERS for those who have not gotten to the 5th boss cell and all that. (Played a lot of this with some STUPIDLY lucky runs recently, Hell really is a good way to put that difficulty...
But I'll do my best to keep this semi-vague)

But fighting that final boss in the Observatory, I ran into an issue. I had thrown my Javelin and hit the far wall to the left of my screen after his second healing phase (i think that is what it is? I'm calling it that anyways) And I had yet to teleport to it.

And we shifted to a different area and I went to throw my Javelin again, forgetting that I would teleport to it instead of throwing it-- and caused me to get shunted back to the previous area with my camera glitching out beyond belief.

After about 30 seconds of noise and glitchy cameraness, the boss just straight up died. (by falling to their death I think, not sure but it went from around 75%ish hp to dead in an instant)
I was stuck in an area with no way out so after restarting my run I apparently still had the boss fight count as completed with no other issues.

Any thoughts on this one? And can anyone seem to replicate it? I honestly wished I had a recording software of some kind when this happened. I got an amazing lucky run and I end it with a glitch. ;-;