Tbh I can see it from both sides. Would be equally angry if I had purchased a paper ticket in good faith from the club and then get a ST holder coming along to chuck me out of my seat... Where am I supposed to go if the ground is full? Equally, I would also be livid if I had paid for my ST seat and someone else was in it. Seems like it will be imperative in these situations to have proof of purchase on me.
Paper tickets are proof of purchase and if there are issues with a ST smart card, then they should really be going to the ticket office to confirm whether they: have been moved seats for the game; CCCS hasn't gone through or; their card is active for the game. The club do need to do better in this respect but there is too much snobbery towards ST holders, when they may have been moved, not activated via CCCS, had issues scanning in and bunked in with someone else rather than going to the TO to sort it out. The club need to figure this out for the cup games and the resolution is very much on them as you just can't have two fans battling for the one seat in the stands during a big game. I can see it from both sides and it is an extremely frustrating situation for both.