Unsure as to what Ernie Wise had gone to Camden Lock originally for (presumably to promote something is the usual reason) but I suppose it may have been a case of the show must go on.
Although it's not a million miles from BBC Radio Four's highly listenable (and very interesting) audio obituary programme 'Last Word' on a Friday afternoon.
That programme is live, and has on occasion covered a death of someone well known on the day of transmission, and someone very close to them talk about them live (or recorded very close to tx), with no wobble in the voice, or breaking down into blubbing.
Ernie was a very good actor, so it could have been he was merely playing the part of 'Ernie Wise' who would talk about Eric in that way, rather than the real 'Ernie Wiseman' who would be far more upset.
My user name might look like Hatton Cross, but it's pronounced Throatwobbler Mangrove.