Pull the other one mate, it's got bells on it!
Ya must come from 'Strylia, where under-arm bowling, two handed hammering and one handed chainsawing is the norm, eh?
No way would any safety conscious forestry worker or farmer use a chainsaw 'one handed', except in exceptional circumstances.
In fact most if not all chainsaw manufacturers tell you not to do so at all, and I don't think there's a chainsaw manufactured as a one handed model.
If the saw bites into the wood and kicks back, it'd take two hands to control it, so your body's got to be out of the way, unless it's a lady's little electric hedgecutter, which even our intrepid Latindancer couldn't control safely.
It takes more than the average bloke to use a chainsaw one handed. it can be done, at the risk of compromising safety.