I stated the first article is an opinion piece:
At the bottom of the article there are some examples.
Another Article no sure as to the validity of the source but:
Coleman's legal team had intended to submit copies of thousands of ballots as exhibits, but the judges disqualified them as evidence Monday because campaign workers had marked on some envelopes. On Tuesday, much of the panel's time was spent with state officials, lawyers and court staff working out a plan to get about 11,000 rejected absentees to St. Paul from counties throughout the state.
Anyways the article shows a classic case for a 14th Amendment Violation. Due to using differing standards in each county it violates the "equal protection" clause of the 14th Amendment, it is why the Supreme Court ruled against Al Gore in 2000, and could render the recount invalid.