No it isn't, for me. But if he's a noob, then it's best to be cautious then have a clipless moment due to inexperience, damaging your bike, injuring yourself.
DittoI went from never riding clipless straight to spd-sl - doddle.
I'd recommend just getting stuck in.
It's a fact that it's harder to pedal with SL's as a regular pedal (to gain speed so you don't fall over, to clip in then start pedalling)
You can still turn the cranks on SPD-SL's without being fully clipped in just treat it like a regular flat pedal until you gain momentum.
Equally you will be fully clipped in on one side before setting off and can continue to push/pull with one leg if need be to continue momentum temporarily.
If you are worried about falling over or damaging your bike then you should stay inside on the turbo