He broke his pattern last year by changing the orders in october. At a time intel was already aware of Meltdown and with a puplication date for the vulnerability set in January. Wikipedia states that the issue had been shared with manufacturers in July, a month after he normally issues his orders mentioned by the article.

Edit: The date on the last part is wrong, which doesn't change the fact that he changed his orders in the time between internal and public disclosure of Meltdown. I misread the article, in 2017 he issued his orders in February not June (2015).

Only time, not number. The schedule allows for a sale on pre determined days, and on the day in question, after he had the news, he sold every share he legally could - way more than he usually did on the scheduled days.