I 100% get where you are coming from; however, in the ER setting, multiple non life threatening conditions could cause these symptoms (I assume paramedics don't get as much experience in in-hospital settings, please correct me if I am wrong as I am not from the US!)
That said, there was a cascade of errors that ultimately led to this very very unfortunate outcome (that maybe could have been prevented, or maybe not)
Had the chest x-ray been ordered perhaps his enlarged heart could have been noticed in due time.
I do not mean to be pretentious in any way. I hope my english does not interfere with this.