Can you file a wrongful termination lawsuit if you have a new employment?

In an unlawful firing the issues are was he illegally fired, normally requires proof of discrimination, and then what are the damages. If he did not miss much time for work his damages will be small unless he lost pension or other valuable benefits.

If one can PROVE that one had an Employment Contract that was breached, or that the termination was solely due to race, religion, national origin, gender or sexual orientation, then there would be a Wrongful Termination for which Damages could be demanded... the new job would reduce the damages, but the loss of income and loss of benefits and loss of reputation would still be losses. THE TROUBLE IS is the worker only lost one month of wages so the damages are at most $10,000 no attorney will be interested because the attorney would have to do about $25,000 of work for a $3300 recovery... a serious money-loser. If you have the experience and excellent reading skills to represent yourself, you can proceed without a lawyer... but 99.9 of people could not represent themselves in a wrongful termination action in superior court, and it costs nearly $500 just to file the documents and $150 to 'serve' them (if you serve the corporate representative properly the first time, unlikely).? Then be prepared to miss work once per month to appear in court to report progress on completing 'discovery' and getting the matter ready for trial.

Of course, he can sue.

Any claim your grandfather may have did not disappear once he found a new job. However, the wages from his new job may be taken into account in determining the damages your grandfather suffered. The suit likely would be against his former employer, and not his former manager, though you would need to speak with an attorney to be sure it all depends on the exact facts of the case.