1940 Destroyers

[1916]

I have no clue why (and I have screenshots I'll post when I can get acess to my PC) but when I snuck into Heartlepool (sp?) in 1940, I got right into the middle of the base in a type IIA and the destroyers were acting wacky. I fired one at a small freighter, it bounced off of the side because of the angle (it was moored so I couldn't get a good shot at it). I put 2 into the side of a C2 freighter, and then the last 2 into the side of an armored freighter (impact but no fire or sinking). Two destroyers picked me up (I got the order to commence hostilites against the Allies half way from base). The first one for some reason took a direct turn into the dock and exploded on impact. The second pinged me, picked me up on the scanners, and then sped up to drop some depth charges on me (I guess, he didn't drop anything though). He sped up, tried to ram me, missed, and sped straight into the dock, blowing up on impact (I've even got a screenshot of bodies flying away from the vessel w/o any mods). Is it normal for destroyers to sink themselves in this manner? Because I think I might have an easy life in 1940 with these kinds of crews.