First hit from back row question

[refnrev]

I've watched several games recently since one AD accidentally booked three officials for several games. Good thing was that it let me watch a lot of good MS games. Two officials (not working together, ever) made this call all season, but no one else over did. On a ball played to a back row player behind the attack line, when the back row player had a two handed overhead return (like a set) towards the net both always whistled illegal hit. There was no prolonged contact, the ball didn't get anywhere near enough to cross the net, and it was always in the general vicinity of another player. I saw this same play many times but it was never called by another official; only these two. Isn't this a legal hit so long as it goes towards another player and does not cross the net?