What are the effects of being on 20mg OxyContin, 3 times a day for patient with CHF and poor heart?

Patient was already having shortness of breath in stomache area. He had slight chest discomfort of 1 on a scale of 1 to 10. He had CHF and at the time when EMTs arrived upon their exam his EKG was fine but had slight fluid on lungs. Emts suggested he should go get checked out due to past cardiac history. He could not lay flat on stretcher and kept telling them he has shortness of breath when lying flat. They gave him morphine per their "protocol" to "knock him out for 45 minute ride to hospital". Immediately after the injection he had heart attack. They gave him Narcan and he coded 7 minutes later and died.

Is it proper standard of care to give a heart patient morphine when the patient was already on oxycontin and the EMTs knew it because they had a copy of the list of his meds?