Postmortem question.

I own a 2015 with an L83 with 65,000 miles. I had 2 collapsed lifters on the same cylinder within 6,000 miles. This time I did a full delete with a Texas Speed stage 1 cam. So, the problem should be solved. However, I am still stuck on the why of it.

When I replaced the AFM lifters the first time, I cheaped out and didn't replace the VLOM. I did tune out the AFM so it wasn't going into V4.Only thing I can think is the the VLOM was bad. Anybody have insight?