The effect on his pension is negligible at this point. Fake news about his pension is so widespread it’s likely intended to fool people into thinking ‘he’s been punished enough’ so prosecution isn’t necessary.
He needs to be convicted of one of a specific list of felonies before he loses his pension.
I don't think he is home free on the pension. It looks like getting fired for cause before turning 50 causes him to lose medical coverage and and he can't draw his pension for another 10 or 12 years. If he had 25 years of service, he would have been able to draw the pension sooner.