Even side could have been torqued wrong. I would also check to see if the exhaust is somehow plugged on that side. It would be unusual for the head gasket to blow on all 4 cylinders unless it wasnt torqued properly. It would also be unusual for the rings to wear just on that side.
I have also seen loose spark plugs cause valves to burn. Were they all tight. I was thinking maybe someone changed them and never tightened that side.
Also more history would be helpful. Was this a new build, were you driving it and it started running bad. Poor valve adjustment could also be causing your issue
Artificial Intelligence is no match for Natural Stupidity