Given that Holden was apparently previously fired for forgery (and did not have any felony on record), it seems more likely that Holden would have committed forgery in a call center job than murder as a technician.

Jumping from forgery to murder seems like a big jump to me.

Additionally, going back to an earlier counter-factual, suppose that Holden actually did murder someone before and finished his sentence and now further suppose that Charter agrees with you that it would only be ok to hire Holden for a call center job. Suppose that Holden then murdered a supervisor that he was angry with... don't you think that people would have expected Charter to have been held liable for the second murder?

You could imagine imposing additional restrictions (e.g. "only virtual call center jobs where he would work remotely"), but at some point, the restrictions would be sufficiently outside of Charter's normal workflow that it wouldn't be worth hiring Holden... leading to a chilling effect of hiring former felons.