You know how they say, "anything you say can and will be used against you"? Lawsuits are like that too. Often it's better to say nothing than something that can be used out of context in court.
The more people that are given information relevant to a lawsuit, for example, the more people and documents that can potentially be subpoenaed. Even if the information itself is harmless, this could add substantial expense and hassle.
I didn't get that bit. What does the author mean by legal issues and why should it be taboo in a meeting?