Jimmy was playing really well in '82. From memory, he seemed to have a bit more pop on his serve, he was netting his dtl fh less than he had been for the last few years (a constant problem for him over the years - an effective but low margin shot), and he was effectively getting to the net.
Should Mac have won? So hard to say. Mac had come off the boil a bit from 81 when Borg was still around. Lendl had been beating on Mac in 82 and Mac hadn't figured out a way to solve that riddle.
Connors was always going to take a match right to your face. He didn't always win, but I can't remember him ever loosing a match (i.e. giving up, not caring, mentally checking out). You got everything he had to give on that day.
So a Connors in good form, Mac a tad off, Connors taking it to him, Mac maybe mentally not 100% - I can see Connors taking Wimbledon.