It doesn't have to be a severe accident. The EMT doesn't want you to remove the helmet. They want to be in control of the situation and remove it themselves.
If you are in a situation where you are not breathing the helmet has to come off so they can get to your face. The pressure from the air bag would be on your skull, not your neck. There would be neck movement to get the helmet off even if there isn't any pressure, but by that time the EMT has done a triage and determined the helmet needs to go even if some risk is involved.The plastic lift strap is no different then just yanking the helmet off. You put a lot of pressure on your neck when you, or anyone else pulls a helmet off.If other sactioning bodies are mandating it, then we should too.
The system has both an EMT kit that does not require individual helmet install, as well as the individual racer unit that is to be pre-installed under the liner on helmets with removable liners. No removal liner? Contact them. On the individual kit, you are to pull open the liner and check the device installation prior to every
use of the helmet. You should carry a spare, since if it did dislodge, the adhesive might not stick a second time. It is dated, and should be replaced every 2 years.