honestly, about 55% of the time, it is town
Actually the chance of both cop and gs being simultaneously hooked is 1/25. That being said, someone using those statistics is doing it wrong. The only one that really matters is the odds of the gs being hooked, which is 1/5 or 20%.
Assuming the mafia hides the gun every time, the gs has a 2/5 or 40% chance of gunning maf. Which means to the people crunching statistics that it's more likely the gs gunned maf than was hooked.
The problem is that mafia doesn't always hide the gun. Unless you know the probability of the mafia to hide a gun or reveal it, those statistics are meaningless.
it is correct to state "mafia killed cop and hooked gunsmith is a low chance" because the chances are 1/20. however, it is wrong if one says "because cop is killed, the chance of gunsmith being hooked is too low" because role of dead guy is independent of the hooked target
as a side note "the chances are too low that the Mafia killed the Cop and hooked the Gunsmith." is a logically wrong sentence. Role of dead guy is irrevelant of hooked person. If someone is using this logic to calculate odds, he is bad at statistics.