Not 'might have been', \but absolutely IS a Spider Bite. If your bike was under warranty or had an extended service agreement you should not have had to pay for the repair - in fact maybe you should send the bill to Yamaha for reimbursement because this was a latent defect.
I don't know how I missed the original thread because your description was absolutely classic.
Get your *** over to the NHTSA web site and file a report (you'll find the proper link in the thread I point to in the next paragraph) - if this had let go while you were riding in traffic, you'd be squashed flat. If it happened at night when you were riding a twisty road at the side of a gully at night, your broken, dead body might have been located a couple of weeks later - if your heirs were lucky. Hopefully you would have died instantly on impact.
Read up
HERE to see just what this is all about. This is a serious design defect that seems to have affected as many as 20% of the Gen-II bikes so far and the NHTSA is doing absolutely ZERO about it. Yamaha has been sitting on their hands for more than two years and are only just now starting to investigate the issue, to a large degree because in Canada the government has rated the issue a 'Level 3' investigation - if it hits level 4 they will not be selling bikes in the country. Period.
The connector in question has been made brittle by the heating that takes place. Grease or no grease, the problem WILL recur. Brodie's harness is a stopgap, but you need to replace the connector to get the full benefit and even then it is a real piece of lame engineering.
That your dealer found the issue and 'fixed it' in $90 (what is that, an hour? ) means that they knew EXACTLY where to look.
Add your name to those whose bikes have suffered the dreaded bite and maybe you should also be calling the NHTSA (and maybe your Congrersspreson - politically correct - as well) to ask them why they haven't initiated a program (in spite of what others may try to claim - there is NO investigation open at the NHTSA). Those are YOUR tax dollars they're spending and you deserve the protection that the agency is supposed to provide.