Strange cam specs

I posted here because I know you guys have a lot more knowledge on this stuff than I do. I'm not arguing, I'm trying to understand.

The only weight on the plunger is the weight of a carbide pilot (that is being used in place of a pushrod) and the spring pressure from a dial indicator. I'm sure the total pressure on the plunger is less than 1 pound. That cannot collapse a lifter. So why is the measurement inaccurate?
As long as you're comfortable with it, go for it.