[glorgau]

The set of "different sequences" that can be stored with the same MD5 key is finite. What the guy should have had to prove is that the speed number presented to the court was possible given the actual speed that he claimed to have been traveling.
All that said, good for him in coming up with a novel arguement for beating a traffic ticket. ;-)

[Moral Hazard]

". What the guy should have had to prove is that the speed number presented to the court was possible given the actual speed that he claimed to have been traveling."

It would have been an interesting intellectual exercise, but he would have to have access to the original data to prove it. If he did, there's easily available code to hack the speed value to whatever he wants it to be and still get the same hash value.

The problem would be that some other part of the data would end up being turned into garbage data to correct for the change in the speed data. His best hope would be if there was some empty space in the data record, like uninitialized space after an array, that he could modify.