Satoshi uses British-style spelling (ie, “optimisation”) but in others, he chooses US style (ie, “criticized”).
 
au.linkedin.com/in/agulhati
The Indian educational system follows British spellings (being a former British colony) Ashish pursued his bachelors degree in english in India, Delhi Vishwavidyalaya, B.A., English Literature (1993 – 1996).
He also studied in the US, Willamette University (1991 – 1992) and Swinburne University of Technology MIT, IT (2009 – 2010).

Such a person could use British and American English interchangeably without even knowing it.
Its should be a fairly common trait among Indians who have their education/work split between India and US.

My drop in this sea of speculation.