OT from ASAJ, but this involves Roger Davis and a non-DS role, so - I'm rewatching the series and I'm currently at #656, from Dec., 1968. Maggie has just become governess and is with David and Amy, who ask her if she knows where and why Vickie left. She tells them that Vickie went to be with her husband, Jeff/Peter. David then asked why Vickie didn't even say good-bye before leaving and Maggie replies that she couldn't because she had to leave on the "spur of the moment".
This phrase resonated iln my mind for a second and I remembered - Roger Davis had a small part in a Twilight Zone epidsode entitled "Spur of the Moment" in 1964. He played a rejected suitor, as I recalled.
I wonder if the DS writers put that phrase in as a joke of some sort, or maybe it was just a weird coincidence?