Steps to reproduce:

1. Spawn a creeper or a pillager while in Creative mode
2. Grab the spawned mob's attention
3. While the mob is looking at you, switch to Spectator mode and move a couple of blocks

Observed result:
The mob continues to look at you for a couple of seconds after the switch before stopping.

Expected result:
The mob does not look at you after you switch to Spectator mode.