Invasion of privacy

While this is unfortunate and highly unprofessional, it is not unlawful behavior.  The invasion of privacy is quite specific as to what constitute an actionable offense, and it appears on the facts presented that none of the elements of this tort have been met.

Possibly, if what was told to your husband was untrue, there could be an action for defamation.  However, again, based on the facts given, it does not seem to be a factor here.  If private medical information was disclosed that could be actionable but there is also no evidence that this occurred.

Unless this conduct breached a stated company policy, violated a union/employment contract, or constituted some form of discrimination/retaliation,  there seems to have been no illegality in this case.