No I wasn't shifting gears, I was actually standing up and doing a small acceleration, because the red light (up ahead) had turned green; I was totally focused on the traffic at the time, because it was so heavy. It's an absolute miracle I didn't land on a car or get ran over, something in me automatically took over and I (without thought) jumped up, grabbed my bike and jumped off the road.
I've locked up my gears also while shifting -- I know that feeling --, but like I said I wasn't shifting I was actually standing up. I do have SPD and they are laced with a velcro strap at top that covers the knot. Kind of like this model
BONTRAGER SSR MULTISPORT SPD SHOES « Handsome Bicycles
They were still secured.