This is very similar to the problem I had with my ignition switch at RAA IV.
I rode in some really pouring rain and the bike sat in a downpour. Had intermittent problems starting it so I pulled the ignition switch apart with the help of xhdskip and cadfather (thanks again guys). Cad cleaned all the ignition switch contact points and we checked for loose wires / bad solder points (none found). Put everything back together and still had intermittent starting issues. Fix was to jiggle the key a couple of times until good contact was made. Rode the bike home and it has started no problem ever since. Weird!!!
Looks like I need to either find a cover for the switch or move it as I am confident another soaking would cause it to not start again.