I hope he fitted a ciruit breaker rather than a switch craft !
If the fitting was properly supported it ought not be an issue for the wiring. However the wiring could be dodgy anyway. Or there may be a dodgy connection causing spikes and blowing the bulb.
As others has suggested, one need to take a look, try all the connections, check things are ok.
Probably not the issue but you have't got something else switching on from time to time and causing spikes on the supply have you ? Boiler/freezer/whatever ?