A lot of blame need to go to limesmen
They do a lot of food work fighting scurvy, but I agree with regards to head injuries they are hopeless
But hard to argue against this. It's cheating, worse it's putting at risk a colleague who does have a serious head injury by lowering patience, acceptance and understanding of potential head injury situations, just to gain your team and advantage. Crying wolf, basically.
Off the field would solve it but disadvantage any team with an actually injured player. Whilst you'd hope that a quick check and recommendation for playing on or subbed is possible, I'm not sure you're actually supposed to move someone with a suspected head injury though, so could be some players specifically taking advantage of that too as they know the initial check has to take place regardless.
So I think we're stuck with the process for checking for extent of injury, and that brings into question retrospective action for cheating. How do you prove it? I mean, we all know really and often it's the same culprits, but what if this occasion literally is the time that one player does have a serious concussion? Often these players themselves initiate the contact to go down on purpose. There may have been contact, can you take a chance? They know it and they abuse it.
I think we're stuck with what we have, but refs should insist on players leaving the field. If I was the official, I'd sure want my arse cover in cases of serious head injury, and asking them to leave the field after an initial check is the best way.
I can eventually see technology and monitoring coming into this. Players who show irregularities in heart or brain functions and game stopped. But players and clubs will still find a way to cheat, it has become ingrained as a 'tactic' especially when facing superior opponents.