My bet is the punched thru rocker had zero to do with the failure. You are taking a old stamped rocker, adding spring pressure, adding addition travel in the wear area. Seen them pop a hole thru many times from this scenario. Most times througha rocker back on and it's back in business. Did this a lot when I was young, poor, and lacked knowledge. Knocking the head off the intake could've been a tight guide, nicked stem, who knows. My bet is the cylinder wal crack may have started the whole mess.
Doug