I kind of sympathize the engineer who had to code this in the first place years ago. I could see it, it was probably a junior person being thrown into it. He would have had to deal with non-standard components, incompatible packages and limited memory, and had a manager breathing down his neck because the manufacturing line was starting up.. He's probably looking up at the clock and thinking that it had enough bits for the foreseeable future.
I'd be a bit surprised if anyone even checked, it's easy to type int out of habit when a number is needed, or even if the dev did consider it the code building and running might be enough reassurance.