For private flying that may be the case but for flying under an AOC under EU OPS or the ANO that person is called a copilot and must be properly qualified.
Don
But then you must question the use of the word " safety pilot" in regards to AOC ops indeed they are co pilots.
For me a safety pilot is a person who is there as a backup in case of an emergency ie in the case of incapacitation of the pilot or where the workload gets so high in certain situations that the safety pilot can take on functions which will reduce the workload on the pilot.
In normal operations he is not needed or required by law for the operation of the aircraft and is purely a safeguard.
The above is the relavent bit. With an AOC regulations require the safety pilot to be more than a passenger with ability and hence he is not a safety pilot in the true sense.
Pace