Exactly. It is implied (legally for this use case), at least in the United States of America. I don't know about outside the USA.

If I detect breathing or a heart beat, I am required to tap you a couple times and ask if it's ok for me to assist you. If you can't respond, consent is still implied. If you respond with anything suggesting "no", then I am to leave you alone and notify emergency personnel that you declined help.

If I am permitted to help, (you give consent or can not respond), then I must only do things that are within my training. If I step outside the line, such as administering a miracle pill (from Miracle Max), then I am liable for resulting damages. If I stay within my training, then I am protected legally.