Today I re-discovered the value of RTFM (Read The Friendly Manual). I was wondering why
var assem = Assembly.LoadFrom("packages\Google.Apis.Core.1.21.0\lib\net45\Google.Apis.Core.dll");
was giving me, for
Google.Apis.Core, Version=126.96.36.199, Culture=neutral, PublicKeyToken=4b01fa6e34db77ab
It's all explained in the dotnet api documentation, specifically
If an assembly with the same identity is already loaded, LoadFrom returns the loaded assembly even if a different path was specified.
This is an explanation that stops me heading off to DEV or StackOverflow for help (that would inevitably point me to the friendly documentation that I should have read in the first instance). For all that, it's still VERY annoying.
A solution to my problem was found at (hmm) read the docs