It's almost impossible that by July she had not been made aware of the problems VW was having with the EPA and CARB. However, that doesn't mean she knew any more than that about what was going on, especially since VW hadn't admitted that they were cheating tests at that point. I think the Green Party is just trying to make political hay out of nothing here. Knowing that there was some issue doesn't equate to being involved in a coverup.