I've often thought that too. He also wrote in British English - using 'ise' instead of size. E.g. Recognise instead of recognize.
Discussion
*ize not size lol
That was also my next comment. English language automatically is 's' and not 'z'
I find it difficult when working sometimes because I always get corrected from our USA audience which is our bigger one too. my spell check and phone automatically puts the 's'