Technology existed in 1972 that would have allowed someone to produce a milimeter-perfect replica of a Word 2000 document such as these, if they'd wanted to take the time to do it and if they had specifications for exactly how the characters should be spaced.
The question is not whether it would have been physically possible to produce these documents, but whether someone in 1972 who wasn't an experienced typist and wasn't interested in doing anything fancy typographically would--by chance--produce documents which happen to match the spacing produced by a computer program that wouldn't even be written for another couple decades.
To use analogy, suppose that in 2006 Microsoft changes its default font to Tahoma 11, the default side margins to 0.9", the default tab stops to 0.55", and the default top margin to 0.75". Suppose further that Microsoft decides (for some reason) that military ranks and dates should be written with smallcaps in place of lowercase, and that recognized acronyms should be written entirely in smallcaps.
Suppose further that it is the year 2008 and someone introduces a document, supposedly from 2004, which happens to exhibit with all of the above document settings and behaviors that appeared in Word 2006. Further assume that some acronyms, which don't happen to be in Microsoft's list, remain in allcaps.
Would you assume that somebody in 2004 magically happened to type the document so as to match the behavior of Word 2006, or would you assume that somebody in 2006 would think Dan Rather enough of a moron to be fooled the same way twice?
Note that there would be no question that the document could have been produced in 2004. But would it be plausible to believe that any such document was produced then in the absense of a causal relationship between the document's creator and Word's new behaviors?