'Let's blame Rolf Harris'

I, and some of the Green wing writers, and two of the not-Green Wing writers, are maybe about two thirds of the way through writing Campus, which is the thing that was piloted last year. It's being written sort of in the Green Wing way, which is to say we have some very vague ideas for plots, then we all write quite sketchy sort of scenes that hopefully fill those plot gaps, but also are ideally funny in their own right. This method does have quite a high attrition rate for material, which combined with me writing in sketch mode rather than normal scene mode means I end up operating a sort of 'fire and forget' policy. Which leads to this kind of phone call:

PRODUCER: Just wondering if you explain the end of this scene to me.

I look up the scene. Two people are talking for a bit, and it ends with one of them saying 'Let's blame Rolf Harris'. Which doesn't really tie in with what they're talking about. At all.

ME: Um...
PRODUCER: (helpfully) I think perhaps you missed a couple of lines.

I stare at the scene again, trying to think of a couple of lines that link the penultimate line (something about a sexual vigilante called 'The Mucky Whale') to the line 'Let's blame Rolf Harris'.

ME: I'm not sure I did. I think... at the time, that seemed like a reasonable ending.
PRODUCER: (gently) Is it possible you're not re-reading these before you send them?
ME: That is certainly a possibility.
PRODUCER: Could you perhaps give that a go?
ME: (warily) I will try.

Later it occurs to me I don't even read them while I'm writing them.