I didnt catch the game so its difficult for me to comment, but looking at the bench, subs made and goal times, your only really talking about bringing on mulumbu, who hasnt exactly looked up to speed when I've seen him play. Given the headless chickens the centre midfield and entire defence became (going by the highlights ive seen),I dont see what else could have been done. I also think you are overly harsh on Rudd.
We lost both our main defensive midfielders pre match, mulumbu doesnt look up to match speed when ive seen him play, in spite of that with 25 mins to go we are 3-1 up. A manager and goalkeeper cant account for half the team switching off.
All we have learned is you have to play at least one of either Tettey or O'Neil, because there isnt the concentration among any of our defenders (midfield and back four). Our famed team spirit, its a paradox, we are just as likely to crumble under a bit of pressure as we are to stage a fight back, but this group are mentally weak on the whole. There are poor performers thoughout, but Russel martin, Newcastle, Everton first half and yesterday, if he doesnt have some sort of screen, goes to pieces.
We really have to consider switching to three at the back with wing backs, much like Southampton did when they couldnt stop shipping goals, needs someone vocal in the middle though, hopefully thats Klose, 3-5-2. Ironically if we did that I would also bring back Ruddy, Rudd is not to blame for the above but hes a shot stopper, Ruddy is the better at dealing with crosses.