1999 Chevrolet Camaro

Engine Mechanical problem
1999 Chevy Camaro 6 cyl Automatic 74000 miles

We had the lifters replaced in May 2008. Just this week the engine failed and we took it back only to find out the noise was coming from the back of the engine. The pan was pulled off and metal shards were found in the oil and located a piston rod bearing that was shot. I'm a mom and I don't know anything about engines. Could the replacement of the lifters in May cause the problem with the piston rod bearing. I just don't know enough about this to really ask the right questions at the repair shop. I just want to make sure I am not being taken for a ride. Any feedback would be great.
June 11, 2008.

I do not see lifter replacement causing a rod bearing failure. But why where the lifters replaced?

Jun 12, 2008.