Ex-Employee joined new firm without relieving order - How this situation has to be handled?

One of my Ex-Employee joined new firm without relieving order. She did not serve notice period in our concern, the reason she stated was medical. But she immediately joined the new firm. A mail was sent to her employer regarding the same. Is this right or wrong ? Her husband knowing the same called and threatened me and used bad words... How this situation has to be handled?

Dear Usha,
What has happened with you is unfortunate.
If the employee abandons her duties and joins a new company then nothing wrong per se to inform the new company about the abandonment of her employment. In fact that company should not have taken her on board without proper verification about separation.
As far as threat by the woman employee's husband is concerned, just ignore it. Consider this as the professional hazard. However, keep your employer informed through written communication about the incident. In case if he calls you on your mobile then try recording the audio call. Never disclose to him about the recording. Be polite from your side when the call takes place.
Thanks,
Dinesh Divekar

Dear Usha,
The advice given by Mr.Dinesh is an apt one to handle such external threats to supervisory /managerial cadre of employees in any organization during the course of discharge of their duties and better urge your employer to take appropriate legal action in this regard .
That apart, your management has to deal with such an act of flouting the terms of the contract of employment strictly so that it acts as an effective deterrent for others. Better initiate disciplinary action against the exemployee for the misconduct of abandonment of service.

Thank you so much Mr.Dinesh and Mr.Umakanthan. I had escalated the same to my higher officials.
I strongly believe an employee should help in smooth transition during relieving. People who cheat the Ex-Employers should face the consequences. We do not hold anyone joining anywhere. But every employee should be responsible and accountable when a job is given to them.
Thank you.
Regards
Usha N

Dear Usha,
I agree with the above two answers but also would like to add some suggestions for it. You can conduct weekly or monthly feedback sessions by the employees in which the employee is free to write anonymously about his needs and requirements. Employee leaves for a cause, working on that cause will help them to stay longer and happily.
Regards,
Tmt Aba