A: We generally don't recommend having a third party in the room for "witness" purposes. While we realize that some attorneys do recommend this, we believe that the negative message this sends to the employee outweighs the minor benefits it brings.
We don't believe it helps the school's case significantly—if litigation develops—to have two school employees telling the same story rather than one employee (as it would be expected that the two school employees to tell the same story). We are very concerned that the presence of a "witness" does send messages like, "We don't trust you"; "We think that you're likely to file a lawsuit against us"; "We are concerned that you may become violent"—none of which are conducive to resolving the matter, if resolving the matter is truly the school's intent. And, if any of these statements is true, then the school is likely having the wrong discussion with the employee—i.e., if you really believe that the employee isn't trustworthy, perhaps you should be deciding to end his/her employment rather than issuing another warning and perpetuating a non-trusting relationship.
(Please understand that this is a brief answer—all serious warning and termination issues should be reviewed with your labor attorney prior to conducting the meeting.)
The primary exception would be if the "third party" is present in the meeting to provide relevant information. Example: If the Head of School is delivering a performance warning to a faculty member, it may be helpful to have the Division Head in the room, so that she can provide information regarding training or other support that can be provided to the employee. In this case, the third party's role is not that of "witness" but that of an interested party who provides information and helps develop a performance improvement plan.