Why did the court impose liability on the defendant in kuehn v. pub zone?

In the case Kuehn vs. Pub Zone, the male Kuehn sued Pub Zone as being liable for a biker gang beating which he was a victim of. Normally a business owner is not responsible for insuring visitor safety, unlesss they have a reason to suspect danger, based upon past experiences. They imposed liability on the defendant, as the jury found that the Pub Owner Maria Kerkoulas knew that the gang in question partook in random violent attacks. This was overruled by the Judge, who ruled that Kerkoulas could not have forseen the specific attack, and it wasn't Pub Zone's responsibility to protect Kuehn from a random outlaw biker gang attack, Kuehn appealed this.