I was having a similar issue, clicking a Button in a column does not cause the row to be selected.
I used the code from commands.zip sample which worked...
Button)sender).ParentOfType<GridViewRow>().IsSelected = true;
I am now moving my code to a ViewModel. My command is invoked and I can pass the bound data object as a parameter but I would also like to select the row. How do I do this from a ViewModel?