That shouldn't be possible in Germany anyways, since helping is a constitutional responsibility.

Therefore no normal law should be able to break your cover. As long as there's no doubt on your good intentions.

Imagine you get to an emergency as a doctor and your patient has a blocked airway, so you perform an improvised tracheostomy, but because you're nervous you cut horizontally instead of vertically and kill the patient. I'm pretty sure as a doctor good intentions are not enough in cases like this.

Of course they are. If you are in that situation, then the patient would die (asphyxiate, probably, since they cannot breathe) without help. The doctor _tried_ to help, in non-optimal circumstances, so as long as the mistake was not intentional or due to negligence, the I believe the law will protect you in most countries.

Remember also that it's not enough to win, you also have to win quickly and cheaply. If that protection isn't reasonably assured, that will tend to bias people towards non-action.