Whilst waiting for ambulance, you are not hospitalised. Once you arrive in hospital or as soon as possible thereafter, you or a relative need to contact the insurer. USA and Lanzarote are well up there for medical insurance fraud. The helpline is there for a reason. In most cases, if you are taken to a public hospital, there is no problem, but some of the private hospitals will start with a skull X Ray, then brain scan and work their way down the body until the eventually confirm you have a broken toe!
I don't write the Policies, I'm only pointing out that you must abide by the terms and conditions.