Death not resetting for Killing Spree [GAMEPLAY]

I noticed that when playing ARAM on Bilgewater, sometimes death will not reset your killing spree if you have two deaths. I myself have died at two kills in a spree then respawned to kill someone and get a killing spree after the one kill on respawn. It has happened at least three times for me that I've noticed. I will try to replicate again. I think it only works on the red side of the map but I am unsure, as I have not played as blue side and noticed it. STEPS:

1. Get in ARAM on red team
2. Get two kills
3. Die
4. Kill someone after respwan.