It could have been a sales tactic by the seller to create a sense of urgency.
I don't consider anything on Craigslist a commitment until I am in the car and on my way. I contact the seller, let him know and verify it is still available and will he/she be there at the expected time. The same when I am selling something. It isn't committed until they are on their way. Everything else is just internet noise.
The silliness on many Craigslist posting have me laughing out loud on a regular basis. Over pricing, lack of information, no model numbers, no images, no prices, etc.