Whereabouts do you live, and what was there setting were LEOs would actually show up because a Karen called 911 for this? Also, what took 10 minutes? Did they run you?
This was about 12 years ago in rural Douglas County, Colorado (near Sedalia if you're familiar with the area). County sheriff had a patrol in the area. They came to check out the situation, asked if I would consent to a search. I let them as I didn't have a knife on me.
We discussed the situation, she had said she saw the "flash" off a knife as I approached her vehicle. I did approach her vehicle, thinking it was my girlfriend's car as they drove the same make and color. I had pulled out my zippo to light a cigarette as I approached the car, the car peeled out and left. I was 20 and didn't think much about her actions continued to wait for my girlfriend.
She showed up then the deputies showed up right after (about 10 minutes after the car left).
They told me why they were there, I told them what had happened, I let them do a pat down. They talked to my girlfriend asking if she thought I would do something like menacing people with a knife (she obviously said no). They ran me and I had nothing on my record except some traffic infractions.
They were calm and professional, I was calm and cooperative, we all agreed she saw the zippo, and that was the end of the interaction.
The interaction was probably 30ish minutes, so 40 minutes from when the car left to the end of the interaction with the deputies.
(Edited for punctuation and grammar).