Rain gutter or not, this looks to me like a classic outcome of turning and leaning the bike for a driveway exit to the right, seeing a vehicle, and hitting the brake while leaned. Goes down like a... [well, there are ladies present
].
After too many close calls and learning how hard it is to save all that weight from going over, I always square up to an intersection before looking and going, so if you have to hit the brakes, you're straight up and down with the wheel pointed forward.
And whether a full stop or slow and go, like a yield, I like to also make sure I have power while still straight up and down--this ever since the last time I dropped my bike about a year ago when pulling aggressively away from a curb where I was parked, backed in; and I was in, I don't know, third gear? Lurch, crash! (Oh wait, that wasn't the last time I dropped it: that was a couple months ago when I didn't see my little orange thingy (I was parked in the dark under an overpass) telling me I had a fork lock on: Lurch, crash! Feck!)
I scrolled back (to our left) from the site of the disaster, and you could see that it was still pretty "fresh" when the Googlemobile got there. If it weren't for the delivery truck at the next intersection, we might have seen it happen.