Tonight, an LA Metro bus drifted into our lane while we were stopped at a light and bumped our Model 3's driver's side mirror. I chased the bus for several blocks and talked to the driver, who didn't believe he'd hit us, and in the darkness with a flashlight, I could find no damage (I didn't realize that the mirror was the point of contact until we were pulling away from talking to the bus driver, and found the mirror swiveled forward a few inches on its mount - which certainly saved it from significant damage), and decided to let it go. Afterward, I found a tiny paint chip on the rear edge of the mirror, but it's still a minor incident.
When I saw the bus approaching in my mirrors and felt the bump, I pulled away about a foot to the right to prevent further damage (since I had no confidence that the driver realized what had happened), and reached up to manually Save the Dashcam segment. When I got home and mounted the Dashcam thumb drive, I discovered that the first 43 seconds of the minute containing the impact (which would have been perfectly framed in the left_repeater camera) had NOT been written to the media. It appears that the system only wrote the remainder of that minute after I tapped the Dashcam icon. It's a good thing that I'm not depending upon that clip for legal purposes.
This is fatal flaw of the Dashcam code.