Camera Cull operator with Delete operation deletes all particles

[Viper]

I make a simulation of underwater bubble particles behind moving torpedo. I have a camera behind torpedo which is attached to and following torpedo. I use Camera Cull operator (Frustum) to hide particles out of camera frame. I use Camera Cull as Hide operation. But I actually do not need particles which are out of camera frame, so, I think I could use Camera Cull in Delete operation instead of Hide. But when I change operation to Delete mode then all particles are deleted. I expected that only particles out of camera frame will be deleted, similar as Hide operation. Is this a bug or I just misunderstood how Camera Cull Delete operation works?