No they know Andrea left the town and was picked up somewhere in between....they do not know where. And remember the prison is still filled with walkers, they have not cleared it out yet.
And yeah I did mention that Carl was slipping and that what we were seeing is a return to season 1 where Rick and his group are the humane group. They are the ones that humanity has a future with.
They took the woman with them to the town...they confirmed through Tyrese that the governor had not come back that the plan was to assault the prison....Rick gambled that was the case when he came out from behind the car....if the plan was to wipe them out...unarmed and in the open would have been the time to do it.
We know that Rick and crew went into the dark place....they left a solitary hitch hiker to die...I thought it was great, but it was a shining example of how Rick and crew were slipping from humane and becoming just like the governor. Being accepting of the people was a return from that.
Was it sudden...maybe but then they were just the infirm and the children. All we have seen is them busing them in....we have not seen where they put them or anything like that.