Sure, in the event of a leak, hydrogen is safer than natural gas.
Methane:- As a gas, it is flammable over a range of concentrations (5.4–17%) in air at standard pressure.
Hydrogen:- Hydrogen gas forms explosive mixtures with air in concentrations from 4–74%
and hydrogen flames are invisible.*
That doesn't look safer to me.
*I guess you could mix something with it to makes the flames visible, in the same way that smelly stuff is added to methane for leak detection purposes.
Oddly enough, that makes it safer.
LPG leaks, it has to reach the right mix before it can ignite - so it leaks, and leaks, and leaks, until just the right conditions occur - then you get ignition and the whole bloody house blows up (if you are in a terrace or semi, the neighbouring houses as well).
Hydrogen starts burning early, before a large amount has escaped - and it burns off. Tends lot to form explosive gas clouds.
Plus, LPG has a nasty habit of building up in basements, under floors, entirely un-noticed (this is the reason for stringent safety requirements for boat LPG installations on inland waterways). Hydrogen just floats up and dissipates.