Clean/fair contact in NASCAR is when you're the faster car but you need to make contact to be able to pass. This is most common on one-lane tracks (like short tracks, such as Martinsville). But it can also happen on road courses due to the speeds involved. Racers are not normally upset about a bump & run when it's done with 10 laps or even no laps left if they know they won't catch right back up to the guy because the guy is simply faster.

What Smith is not that. It was very much dirty. He was not a faster car; he just drove far too deep into the corner and used Tagliani as a cushion. But he wasn't faster and he wasn't doing it just to get room. That is why Tagliani was upset -- Smith didn't do it to allow the faster car to win on a one-grove corner; he did it because he wasn't the faster car.

This is a very important decision. Every week, second place can just drive it into the corner and use first place cushion. But they don't. Why? Because they know they can all do it. Unless you're faster and doing a bump & run, you're just being a dirty prick.

So, to me, there is no doubt it is dirty.

Is it justified? Well, Smith and Tagliani may never race against each other again in NASCAR and Smith needs victories if he has any hope of catching up in points. Whereas Tagliani is in the 22 to preserve their owner points championship lead, something he accomplishes in 1st or 2nd. So, I entirely understand how Smith would justify acting like a prick. But it doesn't change the fact that it was a prick thing to do.

All I know, is that it's a shame how many posters of /r/NASCAR don't understand the difference between just driving into someone because you can & bumping someone because you're faster.