I couldn’t see Martin’s face [during filming] obviously,” said Cumberbatch, “he was just a little blob on the pavement, waiting for a bigger blob to land by his feet… [but later] it was really wonderful to see what he’d done on the other end of that phone conversation - I could hear it [at the time] but to see it was really, really, really moving and, him being in shock afterwards, it’s ridiculous but it made me cry.

“

—	Benedict Cumberbatch - Radio Times