At the end of the Lightning Fill-in-the-Blank round on the show that aired on 2015-11-07, all three panelists, Paula Poundstone, Amy Dickinson and Peter Grosz wound up in a three-way tie. Bill Kurtis stated that it was the first time that has happened under his watch [source] (nb: Peter Grosz also stated that three-way ties have never happened either.)
With that, I cracked open my favorite database tool for querying the Wait Wait Stats Page database and started pounding away at the data. The following is the query that I used to pull in panelist scoring data and filtered out shows that were repeats or Best Of shows (which don’t have panelist scores anyway) and only return results in which Bill Kurtis was scorekeeper.
Well, well… it looks like there were in fact two shows in which the panelists ended up in a three-way tie at the end of the Lightning round. The first three-way tie happened when Bill Kurtis was filling in for (now) Scorekeeper Emeritus Carl Kasell back in the show that aired on 2012-08-18. The second time happened just over a year ago with Bill Kurtis being the official scorekeeper on 2014-09-06.
Interestingly, Paula Poundstone was a panelist on the show that aired on 2012-08-18, with Luke Burbank and Faith Salie.
So, that does not mean that the three-way tie at the end of the Lightning round on 2015-11-07 was Bill Kurtis’s first one as either fill-in scorekeeper or as the official scorekeeper.