Stuff happens....
A few years ago, a friend of mine was sailing his 28-ft Cape Dory in broad daylight with all sails up. No other boats in sight -- except a largish trawler. Try as he might, to include tacking and blowing his horn, he could not elude the trawler which eventually caught his shrouds in its anchor roller and dismasted the Cape Dory and did serious damage to the topsides, deck, and rail. My friend believes the so-called captain of the trawler was "otherwise occupied below" and had his boat on auto-pilot even though they were both near the shore. I wouldn't be surprised to learn that this was the case with the powerboat/sailboat accident described in this thread.
While my friend was luckily not hurt, and the other guy's insurance paid for a new mast, new standing rigging, and a lot of gelcoat repair, the paperwork was endless and the repairs took nearly two years to complete.
My friend (and I) now sail by these rules: (1) presume the other guy does not know what he's doing, and (2) if the other guy is bigger than you, get out of his way, and do it early.
Be careful out there folks.