There's two aspects to the time stamps. One is that based on the time stamps, the emails were all copied on Nov 7 2016 at rates of up to 49.1 megabytes per second.* This is fairly high for internet transfers. The other aspect is that the last modified timestamps of all emails and attachments were quantized to a 2 second granularity. This means this was not a hacked internet server to server transfer but was a copy to an intermediary drive that was formatted with the old FAT format.

The forensics show it wasn't a hack. No one competent in security or forensics would honestly come to that conclusion based on what is known. When coupled with Murray's testimony that he personally couriered the emails from a park near American University in DC back to Assange himself, it's curious Murray has not been subpoenaed to name the leaker, also it's curious the FBI had no interest in inspecting the DNC servers or drives.

* The wikipedia article deceptively misrepresents this as 49.1 megabits per second. Both its own sources explicitly say megabytes, and this is confirmable by examining the original data, which anyone competent can easily do themselves if they have doubts.