Well, I hate gravel too:

My last crash was with my city-bike going carefully through a corner
with some gravel. I didn't go very fast, but I did scrape my knee and
Elbow. Not a big deal if I wasn't underways to an important client.

Honesty helped: I simply told he people I looked a bit disheveled
because of the accident and noone seemed to mind, but I must say it
wasn't my finest hour.

The crash itself was stupid. I had seen the gravel, so I went pretty
slow. I cornered and my frontwheel just slipped away. BANG. And there I
am priding myself on my bikeskills ^^ (I used to cross as a kid and
after that 20 years roadracing in the peloton)

Had the exact same thing happen to me, but I have a better excuse, it
was at night. Had a light but I was turning a corner slowly and didn't see
the gravel till I was on the ground. Surprises the heck out of you. Once
that front wheel starts sliding, you can't recover, it just happens too damn
fast.