Strange. This happen to anyone else?

[GTHammer]

Alright well its 1943 and I've been out on patrol for a little while in my career. I've expended all my torps and am heading towards the nearest subtender to reload. Its night so I'm running on the surface at a good clip and suddenly encounter a merchant. I closed a bit to get a better look and soon discovered that there were 3 large tanker/freighters on their own. I have been doing my best to avoid damage at all costs so I decided not to get involved in a deck gun shootout and continue on my preplotted course. I did send a contact report before resuming my course(which happend to be fairly parrallel to that of the merchants. I recieved the, "Good find X Will direct other assets to intercept X RTB at own discretion" message and close it and just as I'm beginning to ramp up the time compression the trail merchant goes down. I hurridly slowed the game back down just in time for the middle ship to explode and sink as well. Each ships demise has been logged into the little scrolling list that is constantly displayed. So I jump up to the watch and scan the seas until I locate the lead merchant. As I do, he too suddenly begins to explode and bursts into flames. All three ships sank quickly and I hadn't fired a shot. I looked into my log book and found that I had been credited with their destruction and their tonnage added to my total. Anyone else have this happen to them? Or have any idea as to why it may have happened?