This isnt so much a missed moment as an implicated moment. The Doctors memento room seems to be where he keeps reminders of his past and his previous companions. Hes got Amys old Tardis toywhich Clara immediately plays with, life threats or no and a stolen umbrella he didnt actually need. Now, am I the only one who ever wondered where Roses stuff went? She came on the Tardis with a suitcase every time, and lived there for two years. She planned never to move out. Months after her departure, her jacket was still in the control room. And what about Donnas stuff? She came with a pile of suitcases and a hatbox! The Doctor couldnt just give it all back, something might jog a memory loose. All the functionally dead companions things are in this room. Anything they left behind ended up in that memento room. Which means, when you think about it, that somewhere in a back corner of that room is a heap of girls underwear, presumably thrown down and run away from by a traumatized Doctor.