It's a big job
Theresa Payton's declaration is that the process of recovering the data is going to be a big job, and since there's probably nothing to find, well, it's a big job:

Even if computer workstations used during the relevant time period are identifiable and locatable, making "forensic copies" (as that term is defined by the Court) of the workstations that may or may not contain residual data of emails would impose a significant burden on OA.

If you cut through the polite wording, she's pretty much claiming that since there's nothing to find, since all the old computers and drives have been destroyed, why bother doing it?

Hiring people is hard
Since they can't do the work in-house, they'd have to job out the project and the process of hiring extra help is, well, a big job:

The OCIO has not had a practice of making "forensic copies" of computer workstations. Ordering a "forensic copy" of electronic media would require OA to outsource the project and commence what would likely be a lengthy and costly government procurement process for one or more outside contractors possessing the requisite technical resources and capabilities.

Of course, the government uses outside contractors all the time. Can anyone spell "Halliburton"? OK, that was perhaps a low blow, but the fact is, just about any of the IT professionals reading this article could do this job. It's not particularly complex from a technical point of view. After all, we're just talking about a big pile of Windows computers.

Bottom line: Hiring people is not an unusual practice for the U.S. Government.

Making forensic copies is hard
Payton claims that making a so-called forensic copy of a hard drive is hard:

Copying the hard drive as described here would usually require less effort than a "forensic copy". Even so, the hard drive copy process, which the OCIO is equipped to perform, can be complex and time consuming, depending on the volume of material within each folder on the hard drive and the number of folders to be copied.

Actually, this is quite inaccurate. It's a lot easier to make a forensic copy than it is to copy a drive file-by-file.

Let's be clear about what a forensic copy is: it's a bit-for-bit copy of all the contents of the hard drive to another hard drive, for later analysis.

If you've ever done a regular ol' backup of your own hard drive (and you have, haven't you?) then you know that sometimes backups get stuck on things like currently running Windows files (called open files), and files with weird file names, files in very deep paths, or files that have very long names with strange characters.

Windows tends to wheeze when copying a large batch of files, file-by-file.

However, when making a bit-for-bit copy, it's a whole lot easier. Instead of booting to Windows, you boot the computer to a utility disk, so nothing is running off the hard drive you're copying. The program that runs simply scans the drive bit-by-bit and moves all those bits from one drive to another, often into a great, big file on the backup drive called an image file.