I know of at least one case, Lightning v. Roadway Exp., Inc., 60 F.3d 1551 (11th Cir. 1995), where the courts held that federal preemption under Section 301 of the LMRA does not apply to supervisors spitting on employees as that is not conduct arguably governed by the CBA.
(And yes I found an old brief I filed in defense of a union where I relied on Lightning as precedence for dismissal of a (non-spit related) IIED claim just to get this cite)
You could not convince me that there isn't at least one incident of a lawyer in a trademark case threatening to take a piss/dump on opposing counsel.
I can almost *guarantee* that exact fact pattern is out there.