Oh, no doubt man!!! I didn't realize it was the real deal.
The hammer pin (solid heat-treated SS) is the one that you currently have in your trigger pin location. It is grooved in the middle for the hammer's j-pin. The trigger pin, (if it is current design which it should in fact be since this is a Gen II kit) doesn't have this groove since this pin is tapped for the screw holes. They have been known to break in 9mm config so they did away with this groove on the already basically hollow triggger pin. (Only the early Gen I kits had both pins grooved, then later on switched to 1 grooved, 1 smooth. Having the near hollow hammer pin could still proove to be an issue in 9mm config in particular, thus the Gen II design.) If this is the case, you can be sure that the j-pin has already worn the trigger pin itself, not to mention the hammer's j-pin has spent it's life fully compressed. It WILL fail like this, especially in an auto 9mm lower. I'd order up another Gen II kit and pull your whole fire control group to inspect the old pins and get a thorough cleaning in. This will also allow you to really clean up the hammer / trigger mating surfaces to get that nice trigger pull / break. I can't imagine how shitty feeling that FCG has to feel with the hammer all bound up like that. I'm surprised it made it this far.
There have been pics of both failures and grooved trigger pins from incorrect installs posted here in the past.
ETA: You could just call KNS and tell them what happened and they will send you a new trigger pin free of charge. I'd also ask for two new screws as they strip easily.