Sorry I´m a little late to post on the thread, but they say that late is better than never...

Are we talking here about the Cape Bon Massacre, also called Palm Sunday Massacre?
In those hectic days when the end in Africa was finally at hand, there were several instances in which Commonwealth and USAAF planes just hacked the Axis transports out of the sky, including their fighter escorts.

Seems like Ultra provided lots of info on the last ditch efforts Jerry was doing to send sorely needed stuff to Africa, and Allied air just capitalized on it, over and over for a period of several weeks.