I find the “analysis” to be quite weak.
It’d be interesting to know the age of the analyst. English usage in the US has slipped quite a bit over the last 50 years.
I don’t have a dog g a n this fight but remember, Ms Ford went to an exclusive girls school so her English language should be top quality
I find the analysis inconclusive, but it also misses a more critical point.
Christine Ford is a widely published author with many professional paper and even a book or two to her credit.
A far more persuasive approach would be to compare the writing style in the letter to writing style in her other published works.
Authors a grammatical style signature that is often quite distinct which allows identification of a documents author.
For example, GOOGLE programmers were able to analyze Barak Obama’s autobiography and determine that the real author was ex Weather Underground terrorist Bill Ayers.
A quick comparison between the letter and Fords other work would show pretty conclusively if she wrote it.