The only reason those words are in the standard entry form is to try and ensure that the disclaimer wording which precedes them will hold water for the protection of the RO.
It is not possible under English law to exclude your liability for causing death or personal injury by negligence.
If a limitation or disclaimer does that, it won't work for the benefit of the person who seeks to rely on it.
The safest way to ensure that the disclaimer language doesn't fall foul of this rule is to expressly say that those liabilities are not excluded.
Causing someone's death or injury by negligence will almost always attract liability; the question of the negligence, if there is an argument, will be determined by the court as in Hedley and Cuthbertson mentioned earlier. Much will revolve around the scope of the ROs duty of care as seen by the court, and the view it forms as to whether this has been broken. That is where evidence and experts come in.
I say "almost" because there are 2 very helpful legal concepts which might help a RO when otherwise he or she might have crossed the line. Contributory negligence (failing to carry the mandatory equipment maybe) and (I won't use the Latin) putting yourself in harm's way. The difference I recall is that in the first, the RO is liable but the liability is then reduced, and this might be by 100%. In the second, liability is never established.
Even if negligent, the insurer should pick up any liability (as with Cuthbertson).
Provided of course that the RO hasn't adversely tipped the scales of risk against themselves by doing something that prompts the insurer to abandon him or her.
Complicated!