What is happening with your friend's husband is unfortunate. Nevertheless, to provide a solution, we need a little more information.
Understanding the Ex-Manager's Role
What is the meaning of an ex-Manager? Has this ex-Manager resigned and is on a notice period? Is it that this ex-Manager's department has been changed, and now he is handing over to the husband of your friend? Why is the ex-Manager abrasive? Is he abrasive only towards the friend's husband, or is he irascible to all?
To whom does the ex-Manager report? Why are his seniors silent?
Analyzing the Ex-Manager's Behavior
We need to understand the psychology of the ex-Manager. Why is he behaving badly? Is there tacit approval for his behavior by the top management? Is his long service being rewarded notwithstanding his poor interpersonal skills?
Since you say that your friend's husband has approached the MD also, but there is no reply from the top office. Therefore, at this stage, your friend's husband needs to generate evidence of the harsh behavior. Let him do audio recording when the ex-Manager shouts. Normal shouting that happens at the workplace cannot be considered harassment as such. However, if the ex-Manager abuses, then it can become harassment, and he might lodge a police complaint. However, this option is fraught with risks. Your friend's husband is new, and he is yet to find his footing in the new company. Incensed at the police complaint, they may remove him on some other pretext.
I doubt whether the ex-Manager can cause any physical harm. Logically, it appears to be far-fetched. However, there is one more option also to solve this problem. Call me on my mobile, and I will explain it on the telephone.
Thanks,
Dinesh Divekar