Lists: Last Activity Date on list activity view is wrong

[George]

This morning, I reverted a record that someone has spammed with an undesirable First Sentence over a year ago.
http://openlibrary.org/books/OL8431394M/

I created a list to watch for the return of a spammer. I returned to look :)

Here's the list:
http://openlibrary.org/people/george08/lists/OL1795L/Watching

If I look at the "last updated" value on both the Seed & Activity view, you'll notice that the "When" value for that edition is wrong. At time of writing, it say "2 days", when the edition page edit log says "5 hours".

Screenshots attached.