As stated earlier, you admitted that the handgun was exposed. This is a violation of the SDA and a CRIME. A police officer stops a CRIMINAL with a firearm. He will probably do so at gunpoint, be very vocal and demanding, probably handcuff you and search you for other weapons, during said search he found two knives one of which he deemed to be illegal. After he ran your drivers license and found out that you had no outstanding warrants he was nice to you except for keeping the suspect knife. That would be pretty standard with any police department in the US, though some would get far more forceful in this type of apprehension and many would have taken you to jail for the knife.
Man up, admit you screwed up, quit whining about the way you wish the law was, we all wish it was, and take your medicine.
+1 ExSniper. Man...this is one of the dumbest threads I've seen yet! (My handgun was showing and I was carrying an illegal knife...now I'm mad cause the po-po didn't treat me very nice). SO FREAKIN WHAT!!! You did something stupid and got what you deserved. If you can't carry responsibly then you shouldn't carry.