This 'phoning home' occurs every time the game is launched, and is independent of patches.To prevent this from happening unexpectedly, you must assert control over when Steam performs such steps.If you have mods that are not easily re-installed, it is advisable to have a complete backup of the game folder tree, so you can revert when a patch does get forced upon you.
Steam has demonstrated that they will ignore the disabled 'auto update' settings for a game without warning (at least sometimes) when the game vendor releases a patch.
The only reliable method to avoid unwanted or unexpected patches is to always run the game in Off-Line mode.
If a file cannot be verified, it is replaced by an online copy which often resolves the issues that you are experiencing.
To verify individual games on Steam do the following: While that is useful if you only need to verify one game or maybe two games, it is not really a solution if you need to verify all games you have installed on your system.
The following fixes will resolve most update and installation errors with Steam.
They can be performed with a minimal amount of technical knowledge.
It simply takes to long and requires too much attention to be practicable.
It is using the Auto It scripting language and can either be downloaded as a script or an executable file.
I explored which file was being reacquired using the same process mentioned in that forum thread and it is even the same file as the OP visible as Steam suggests, maybe that's just old. It raises the question, why didn't it find all the problems in one and then download them all I've no idea, again I'm just taking a guess.