No difference in the tackles Morgan, Gray was that badly concussed he came out the next week and kicked a couple of goals and was in the best players on the ground.
Gray had the ball between hand and foot when Nyhuis started to tackle him to the ground, he was in the field of play at that stage ( What about the times Freo players are ridden into the ground, thrown towards the fence and generally roughed up over the boundary? that all ok?) The Tigers player had lost possession off the footy at about the same stage of the tackle.
The Tigers player was dazed, and lay on the ground for a time after the tackle, and you only have the commentators word, and the Port "medical report" which we have no access to that Gray was knocked out for any length of time.
You are right however, the tackle was different, the Tigers player was initially tackled high, and should have received a free for that, had the arm pinned for the whole tackle, (Gray had his arms free and was trying to break the tackle) and his head slammed into the turf.