Why does Barrier seem to reduce damage like necro shroud does regardless of class?

[Crab Fear.1624]

I often witness hits that would hit without barrier for x damage, and when barrier is up they will hit for .5 x damage.

I know I saw some threads way back when people thought barrier prevented crits.

I think it is the rollover from the necro survival kit, but now any class with barrier gets that reduction.

[ollbirtan.2915]

Have you tried....not posting false claims, maybe?