Family parameters unit in Dynamo

Here is a weird situation.

Dynamo claims to be without units and that they read numbers from Revit as they are.

I have a simple family for which I have added some parameters. When defining a parameter for a family you can select what type of parameter it is and then you can select it to be length, area. force, etc.
In my case I have defined a length parameter and it shows up in properties palette as mm.
My project units is also in mm. However, once I extract this parameter in dynamo it converts it feet!!!

How do you explain this?

It looks like there is an inherent feet unit to Dynamo and can not be changed.
Is that so?

See here if it helps: