Darn it! - a plot hole discovered

"Although it's likely Walpole will have cleared it up" Madigan, one of my characters says, speaking of possible blood and gore.

But there's been no mention by her, or any of her three companions, that Walpole has been involved in anything.

I know it - it's my story.
The reader knows it - the scene appeared earlier.
These folks, in discussion in the bar, do not know of it.
Damn.
I have to tell them, before page 193.