
Assuming the person performing as the mascot is an employee of the Titans and not an independent contractor, the Titans would be vicariously liable for personal injury proximately caused by his unreasonable conduct. Driving a golf cart into an opposing team's player warming up on the sidelines is most likely negligent. But McPherson has the burden of proving his damages. What's a knee bruise worth to a fourth string quarterback? Definitely not $5M. McPherson alleges that the injury forced him to miss the entire NFL season. However, the Titans will argue that the reason he missed the season is that he was cut by the Saints as the fourth string QB and would have been cut anyways, not because of the knee bruise. The Titans can also point to the fact that he now plays in the Arena Football League, and no other NFL team was interested after he was cut.
What is unfortunate for the Titans, however, is that damages are typically a question of fact for a jury to decide, especially in this situation because it involves determining McPherson's worth as a player as well as the issue of whether he would have made the Saints' roster if he had not been injured. So unless this mascot is an independent contractor, the court would probably not dismiss it as a matter of law on the liability issue.
My prediction is that the Titans will sit on this case for awhile. If McPherson continues playing in the AFL, it tends to establish that the injury he incurred was not that severe. And if he doesn't ultimately get picked up by an NFL team, it tends to show that he would have been cut by the Saints anyways.