1974 MG Midget OIL Change

I had an oil and filter change drove 15 miles and as I accelerated up to 70mph the lower part of the engine made a very loud metallic grating noise there was a immediate loss of power.

I have been told the engine is destroyed.

My question is could the oil and filter change have caused the damage as the engine was running perfectly prior to the service work.

Thankyou