By the look of the photo your weight was forward of the BB and as a result it looks like your back wheel was unweighted/lifting whilst the front tyre was under a lot of compression whilst the fork was not.
I'd do what Jedi says and next time look into the next section; let the bike sort it out, you obviously made it each lap so it must be ridable and you will move your weight back naturally if you pump the downslope for speed.

