From M. Pruitt, the most reasonable explanation I have heard.

"BAD ETIQUETTE?

Controversies were kept to a minimum at Milwaukee, but the one item that did flare up—and keeps going—is Dario Franchitti’s pit lane tire contact incident.

The Target driver struck the new right front tire that awaited Will Power as he pulled into his pit stall, sending Penske’s Billy Vincent, who was standing on top of the tire, for a bit of a ride.

Vincent, Power’s chief mechanic, was uninjured, but some fans continue to question why IndyCar Race Director Brian Barnhart failed to penalize the Scot for striking a piece of equipment on pit lane.

The answer lies not in the formal rule book, but in the informal set of rules teams normally abide by in the pits. Teams make a habit of pulling in the left or right front tire (depending on which direction pit lane faces) to allow the car in the forward stall to pull in without any dramas. The team in the forward stall, in kind, pulls the rear tire out of the way to let the car in the stall behind exit without any dramas.

It’s the neighborly thing to do.

The only scenario where teams won’t pull that front tire out of the way is if two cars are pitting nose-to-tail. Had Power been right on Franchitti’s gearbox heading down pit lane towards their respective stalls, Team Penske would not have been expected to lose time by pulling its tire out of Franchitti’s way while Power followed right behind.

The non-call by Barnhart, in this case, was due to the fact that Power was nowhere near Franchitti at the time of the pit stop. The Penske team had plenty of time to pull the tire and step out of Franchitti’s way, but they chose to leave the tire in place…and to stand on top of it…

As one Ganassi team member told SPEED.com on Tuesday, “I hope this isn’t a view of what’s to come. It can get dangerous and pretty nasty if that’s how we want to start treating each other, and in my opinion, there’s just no need for it.”

I’d like to believe it was an innocent mistake by Team Penske; they aren't known for boorish behavior on pit lane, and I’m sure the two teams and the series will make sure everyone plays nicely this weekend."

rh