It turns out to be more complicated than that. While such speed may not be available to a Romanian hacker using an international internet connection, it might be available to a hacker using or connected to a computer located near Washington D.C. with a high-speed cable or fiber connection, provided that the DNC also used such a high speed connection. D.C. leads the nation in high speed internet.
However, it is important to note that the speeds found by Forensicator, 23MB/sec for mixed size files and 38MB/sec for large files, are exactly what you would expect for transferring files from a modern computer to a USB2 thumb drive.
There is more to this story than data transfer speed. For more info, read the articles here: https://theforensicator.wordpress.com/
I have seen that. I think it was most likely Seth Rich.