Although as Kitani was already 51 at this point, combined with Fusjisawa’s crazy blunders, I feel we cannot not rule out they both read the sequence somewhat willing-nilly.
Another issue is time pressure. I have yet found documents about the exact time control format for the honinbo league tournament back then, only that it was a 1-day game. Older generation players like Kitani might be more accustom to longer time format, where they could literally play through the night. I feel I need to dig deeper in the history of time control format and how the custom of countdown emerged in the 20th century. From very old records in the early 20th century, they only count to the minutes instead of seconds.
This is a page from the game collections in 1925(大正14年) of Hiseikai (裨聖会, it was a splinter association that disagreed with the just formed Ninon kiin integration policy, along with the rivalry between Honinbo Shusai and Karigane Junichi). The early format of byoyomi was very different from what we know today. How they changed in between, especially after WW2, the revival of newspaper Go, and the rise of TV broadcasting Go would be an interesting subject to research on.