Delegate Conundrum.

I came across a story today about Hillary Clinton delegate Sacha Millstone of Boulder, Colorado. Apparently Millstone has hired an attorney after she received a Democratic Party email that ordered her to come to headquarters to 'explain' disparaging remarks she made about Barack Obama.

Her attorney wrote the DNC asking for the rules that allow the party to threaten a person’s removal from the state delegation. Party officials say the issue has been dropped.

Now I don't know anything about this particular person, nor her motivations. But this raises an interesting conundrum for the Party - should delegates be free to criticize the nominee? And if so - why would they be forced to 'explain themselves' for remarks they make. Thoughts?