That article has some odd figures in it...
So far in May, insiders have sold $3.8B. Insiders defined as "officers' (excluding beneficial owners, and the like) have sold $2.2B
Insiders have bought at least $218, so far.
BTW, the figure for purchases does not include options exercises, and the figure for sales does not include selling of exercised options (which would add $1B more).