Nearly losing it, (crashing).

Ive havent experienced anything like this, very mild one tbh, but apparently catching some air over lumps can also cause this sometimes.
Steering dampers stop / reduce this dont they?

From what i hear SVs aren't exactly prone to them. Doesn't mean they are immune obviously but it's rarely an issue. Had a vague one once in almost 5 years on big bikes, was on a bumpy uphill right-hander so i deserved it, settled out really easily.

Had an interesting one this morning, must have been a dodgy corner as the rear started sliding out really controlled, not like i hit a patch of gravel or anything, just backed off the power and kept the line, normally i'd have been cacking myself and heading for the other lane. Think it was just because the tyre was only just exceeding grip rather than anything I did to help the matter.

So long as you learn from anything like this then it's served a purpose I think.

Happened to me once on a river road where the road had rippled in a series of long 'speed bumps', pulled the bars out of my hands too! The road had a long brown streak along it when I looked behind! I guess the answer is avoid that bit of road when tanking on!