When I look from a perspective of the defendants being involved, I feel Guede was given access to the cottage.This is especially true for one part of his story: he insists Meredith let him in to the apartment. Why not say Amanda let him in? He could say they all went in together, or she gave him a key so he could get a drink or use the bathroom. Why say Meredith let him in? Then he has to invent a situation where Amanda rings the doorbell instead of using her key?
So, in the guilty scenarios, does anyone really believe Meredith let Rudy into the house herself?
The only possible way I can imagine Meredith letting him in, is if he himself rang the doorbell, said he was looking for the guys downstairs, she told him they were away, and he asked politely to use the bathroom - Under these conditions, I think she may have HESITANTLY let him in, but I still doubt he came in that way.
I've often wondered in his "date with Meredith" story, if it was Amanda who actually "smiled, said, 'have you been waiting long?', got out her keys, and shouted, 'anyone home?'" and not Meredith as he says it was.