The pipe's too close to the consumer unit and the cables and contravenes the regs. This is nursery school gas knowledge.
You might want to post a few pics of the pipework and any other work he did.
Either ask him to rectify (at his expense) or ask for a Gas-Safe inspection and they will force him to re-do it for free (and note his file as he needs monitoring).
From BS6891...
8.16.2 Separation of installation pipework from other services
Where installation pipes are not separated by electrical insulating material, they shall be spaced as follows:
a) at least 150 mm away from electricity meters and associated excess current controls, electrical
switches or sockets, distribution boards or consumer units;
b) at least 25 mm away from electricity supply and distribution cables.