It really depends on what the lawsuit and testimony are about. If it's a frivolous kind of lawsuit that you disagree with, don't volunteer. If the lawsuit is ab

It really depends on what the lawsuit and testimony are about. If it's a frivolous kind of lawsuit that you disagree with, don't volunteer. If the lawsuit is about something that you support, your ethics should compell you to testify. Either way, be aware that you can be forced to testify. As long as your testimony is based purely on facts, then I don't see future employers as having issues with it.