"aside from selling weapons he is not a bad guy"
Sure you know, his work ruins a bunch of people's lives and it does makes the world a worse place by facilitating bad people the tools and means to do horrible stuff, but other than that very important and prominent part of his life, he is pretty nice fella, i think i will even be sad if he dies here.
So the watch has a low frequency sound on it and the brat was using it to count? or better said the chicken guy was using it to count, and then sending the signal to the brat, is that what Karl figured out?