Sleep slowing down projectiles?

[Trickshooter]

Noticed this the last couple of days while playing a Nature/Sonic Defender. When I put an enemy to sleep mid-attack, if their attack has a projectile, it very slowly flies towards me and won't do damage until it reaches me. It was easiest to notice fighting Wolves, and I thought it might be some quirk with their boulders, but then last night I was also seeing it affect Widow psi-attacks. Very strange, not a big deal (actually, mostly funny to see), but nothing I ever experienced before.