Crowd Control abilities affecting other players on PVE servers?

I am on an official PVE server and throughout my playtime (26 hours at time of writing) I've noticed on multiple occasions that crowd control/stun abilities are affecting other players? For example when fighting boss using a mace, I use the swing ability to stun them for a short time; yet when swing i've actually hit and stunned other players rather than the boss themself. It's also happened to me when another player threw their scythe and it did a spinning attack doing knockback, i was launched across the combat zone as if i was an enemy; these abilities haven't done damage that I can tell but CCing your fellow players during a boss fight does hurt cohesion a bit.