Nothing here indicates anaphylaxis to me at all
We need a lot more information; did he have any swelling or redness, hives, stridor/wheezing, laryngeal edema, anything to suggest he indeed had anaphylaxis? Did he have any cardiac history? Medical history? What was his blood pressure like?
It sounds more like a primary cardiac problem than anything else.
If it were my patient, we'd throw him on the floor, quick primary survey, chuck an LMA in, sounds like by that time he'd probably have been in asystole so work him on the floor, oops he died, terminate resuscitative efforts and go back to the station to watch telly.
Sounds like a much better ending and no teenagers involved.