“Probable Cause” featured several guest stars that tweeted about their experience on the set. Gerald Downey who played, Lloyd Kurtzman, thanked the cast by tweeting:
— Gerald Downey (@geralddowney) September 14, 2012
When the episode aired he also thanked fans for their support.
DawnMarie Ferrara (Female Uniform) wrote about being cast in the episode and about her week of filming.
Its official - I booked an episode of ABC's "Castle"! #soblessed
— DawnMarie Ferrara (@ThatDawnMarie) September 11, 2012
What a week: filmed "Castle", writing, catching up w girlfriends, house work & then dealing w hives - Phew, I EARNED this Sunday Mimosa
— DawnMarie Ferrara (@ThatDawnMarie) September 23, 2012
Heidi Schnappauf (Tessa Horton) also joined in with:
@NathanFillion first I'm dead stunt girl on castle, then dead stunt girl at the haunted play two weeks later. Hope you liked it 😉
— Heidi G Schnappauf (@StuntgirlHeidi) October 1, 2012
Norman Dessing (Jack Nicholson Lookalike) also tweeted about his experience, "Got booked for two TV shows---I didn't submit for these roles--they called me. Nice!" and "I'm featured about 3/4 of the way through the episode. It was fun being on set..." When the episode was aired again he simply wrote:
Yes, that was me on Castle tonight.
— Norman Deesing (@normandeesing) March 5, 2013