In Porous Media Corp. v. Pall Corp., 186 F.3d 1077, 1080 (8th Cir. 1999), the Court of Appeals held that the "rejection of the plaintiff's motion for judgment as a matter of law . . . fatally undermines its claims for malicious prosecution."
The Court reasoned that because the applicable Federal Rule of Civil Procedure, Rule 50(a), "permits dismissal when 'there is no legally sufficient evidentiary basis for a reasonable jury to find for' the non-moving party at the close of that party's evidence," the denial of a motion for judgment showed that "reasonable jurors could differ as to whether the defendant should prevail." Id.
In other words, "if reasonable jurors could find in the defendant's favor, it follows that there was probable cause for bringing the counterclaims, that is they were pursued with a reasonable belief of success." Id.