Does being the defendant in a Langham Act lawsuit weaken my position if I'm first to use the name?

Notice: The below is for educational and informational purposes only, is not a reflection on or a representation of any views or opinions held by my employer, and should not be construed as legal advice. Nothing herein is meant to create an attorney-client relationship.

It is not clear from your question whether your friend's competitor filed a declaratory judgment action of non-infringement, or actually sued your friend for infringement. Either way, the facts will have to be flushed out during discovery. Whether your friend has priority of use over the competitor and whether there is a likelihood of confusion based on a number of factors, will all be litigated.

A disadvantage of being a defendant is that you are in a position of defending the case, as opposed to prosecuting it against another. However, the competitor will still need to prove his/her case of infringement. If your friend believes s/he has priority and that a likelihood of confusion exists, your friend should consider filing counterclaims against this competitor.

In any event, I truly hope that your friend has retained a knowledgeable trademark attorney to review the matter and represent him/her in this case. Trademark disputes, and especially lawsuits, are not something one should dive into without seeking proper counsel.