Hmmm
The French sub took sonar dome damage which indicates a bow collision, it's possible that one of them came up through the layer and met the other.
The chances of two missile boats colliding are pretty astronomical, if it was an SSN and an SSBN then I'd say it's the old 'got too close while tracking' story, but two boomers? Boomers don't trial, well, they're not exactly designed for it.
Strange, but true, wrong place wrong time I guess
