when the Villa is under attack u help Claudia escape then the cutscene with the guy with the bandage round his head says where does this passage lead and then u see Ezio close the door and lock it from the inside (I.E anyone in Marios Room wouldnt
1. know its there
2. evan if they found out how to open it, the door wouldnt open as its locked just like when Desmond and Lucy try it, so after desmond jumps off the high wall and shauns annoyingly sarcastic comment u have to navigate the tunnels, well how can Ezio and family be chased buy Soliders when the door is still shut and locked. when desmond starts to see the bleeding effect .
also a design flaw ? when u see Ezio he Ovbously doesnt have time to raise the metal gate around Altair's Tomb but when Desmond and Lucy enter
1. Its up as if its been locked
2. it looks like its been cut open
however the main door in Marios room in the present its still locked and it looks like no-one but Ezio and Desmond and Lucy have ever made it back into the sanctuary room ?