1976 megabytes in 87 s is indeed 22.71 megabytes/sec. Do you think the units used casts doubts on the validity or what?
As an engineer, I'm used to dealing with odd units but as a nonIT type, I don't quite follow your objection.
I am an IT Engineer. They simply used an incorrect phrase. The author was writing this as a supposed expert and I indicated that it was a small nit.