Zimmerman's position gave him regulatory authority over Nestle. He had the power and opportunity to correct lapses in oversight but under his supervision the lapses were ignored, forgotten, or deprioritized. Then he retires and the organization that benefited from this lapse hires him.

I have no problem with skilled government employees taking jobs at a private company as long as the company they're working for could not have benefited from regulations they administrated.

I don't think the acquihire analogy is relevant is this situation.