Learned that lesson as well, almost went down from gravel in a pair of switchbacks that had washed down from a driveway during a rainstorm the night before. Front wheel kicked out then caught again sharply on the clean pavement, could have been a nasty wreck from that but somehow I stayed off the brakes and pulled it out. You just have to be more careful around blind corners on country roads, there is always sand and gravel where you least expect it. Hope you get your bike fixed soon and glad you weren't hurt too bad. I would just take it as a lesson learned, not the farmers fault.