Why did the resupply sub shoot a torpedo?
Something that has bothered me about this movie is what prompted the skipper of the German resupply sub to shoot a torpedo at the S-33? If the shipyard workers ("yardbirds" as the chief states!) did a good enough job to fool the crewmen of the U-571 into thinking it was a real German sub, shouldn't that have also enough for the resupply U-boat? Maybe the resupply sub's captain could have thought that it was actually another U-boat that just happened to find the disabled U-571. If so, firing a torpedo at a fellow U-boat would have been a mistake.
Did it see what was going on (capture of the U-571) and then back off to fire a torpedo?
How did it know which sub to shoot at first?
Why continue to try to sink the second sub (U-571)? If they realized the S-33 was actually a US sub, once they hit it, the U-571 would now be safe.
One answer could be that it shot only one torpedo at the S-33 knowing it was not German. Then, after seeing the other sub (U-571) dive, the resupply sub's captain knew something wasn't right and tried to sink it.
Your thoughts...