Same kind of story happened to a student and instructor, from my flight school, while on a X/C. Five years prior, one of our aircraft was stolen and hadn't been found. Since our school bought a batch of planes at once, we have a few tail numbers that are very similar. I guess that last two digits on the tail number were flip-flopped....and someone messed it up. As they got in the plane they were surrounded by police, who pulled them out of the plane, cuffed and and held for a few hours while clearing up the mess. Student was good, the instructor ripped some clothing on the way out and got a cut on his face from eating the pavement. Arrogant pricks didn't even offer them an apology when they realized that THEY had f'ed up. I'm all for taking necessary precautions, but at least have the balls to say I f#cked up, man up and apologize.