Actually, the IP address can be identified as "Department of Commerce" or "Verizon," with some tracking stuff I am familiar with. Some smaller businesses may have accounts with Verizon (just a for instance), so cannot be further ID'd without legal instruction to the ISP to do so from a court. I think that's what Jim is talking about. I think they could identify the exact computer in O'Malley's office (another for instance) that was used, with the appropriate legal order.
But, since this is Maryland, and Maryland is lousy with RATS, we should not hold our breath waiting for that to happen.
the electronic trail of MD4Bush does not indicate the postings originated from a government or institutional computer. I find the wording of this statment to be very suspicious. If the source had said "the electronic trail of MD4Bush indicates the postings did not originate from a government or institutional computer." then I would say the statement has some meaning. "not indicating" to me means the electronic trail is not conclusive in indicating a non govt or institutional computer or any other computer.