Been said many a time, TMO does not result in realistic AI. It results in tough AI.
In TMO, sometimes The Computer is a Cheating Bastard. And it will feed on your tears.
I've occasionally been rumbled by DDs when they had no logical right to know I was anywhere nearby. But in such cases, I jot it down to what would, in real life, be termed "****ing ****ty *** luck!".
Perhaps a tired midshipman tripped and had some heavy equipment land on exposed metal, perhaps a german POW was onboard tapping out morse code on a bunk with a spoon, etc.
I actually like how the DDs in TMO sometimes catch wind of me for no reason.
Why? Because it introduces an element of uncertainty. Even if I do everything right, they might still catch wind. To me, this keeps it interesting.
Your mileage may vary, ofc, so you might want to try out the easier AI mod Ducimus (read: god's roomate) cooked up.