Im just gonna develop this a bit more so bare with me....
Suppose there are two airplanes, 10 miles apart, travelling at x knots, and in parallel in the same direction. The plane on the left then turns right slightly thus making a collision path with the other air plane. The plane that has changed direction has a radar that's not working. The plane that continues going straight has a fully functioning radar and can see it is on a collision course. The pilot has 5 minutes to change his course to avert a collision. But he doesn't want to and thinks "why the heck should I change course, its not my fault the other pilot changed direction". In addition, due to some air plane rules, the pilot going straight has the right of way.
In 5 minutes from now, they crash. An investigation follows. What would the conclusion be?