Prospective,
I also boat in the same waters and would have made the same call. With the weird weather pattern we have been having, the storms have been moving in fairly consistent manner. If it were a single engine boat, different call. Plus , you know how the boat has been running, boats can be unpredictable, but boats that are runnning well don't usually crap out two engines. Also if you are like me, you run the boat harder at times just to make sure you can do it.
Was this on Wednesday? I work in Groton and there were some fierce T-Storms that day, 5 inches of rain. SE CT and Watch HillWesterly got pounded, Block had the better weather.
Last Saturday I made a high speed run to beat a T-Storm in. The storm never hit as they have been getting pushed off by the bay. Good to know my boat can do 22kts with more power to spare though.