I have found that in some of the convoys, what appears to be the "escorts" are not set to "escort" status, so you might see a corvette-type vessel, or patrol craft, but it is part of the convoy, like a cargo ship, and not set to "chase" anything, and their "attack" AI isn't as strong as a DD. I'm trying to write a little utility app to run through files to find those, so they can be edited correctly, without having to search through five thousand RGG. Also of note, the warship might possibly be set to be the convoy "leader", has no sympathy, and they do not stop for one straggler. Easy tonnage for you - for now...
- in the meantime, did you happen to see if the rest of the convoy begin a zig-zag course immediately prior to, or just after the torpedo impact? Thank you!