His Last Vow DVD commentary:
Moffat: And of course, the umbrella.
Gatiss: Yeah. Who knows what secrets it contains.
Moffat: You’re desperate to have secrets inside the umbrella, I know.
Gatiss: We did talk about having that instead of the laptop.
Moffat: You did try to persuade me that, yes, it was all in the umbrella. That would’ve been… That would’ve been a different show.
#snort