Guy with SOB coughing up blood, partner just went into cardiac arrest for no apparent reason... My first thought is that there is some sort of airborne chemical or something, and I need to get out right now. Screw the patient, I'm dragging my partner's body out of the area if possible (and certainly not going back in for the patient...), calling for additional resources and notifying of potential hazmat situation, then CPR/defib on my partner.
I don't feel so good about CPAP given "chest rise and fall diminished on left side of chest" and "c/c is coughing up blood". If he's got a pneumothorax, CPAP is going to finish him off pretty quickly. Also if there is a lot of blood in the mouth/oropharynx you could cause some problems.