seems Facebook changed the result of posts, few weeks ago it was possible to read the comment count from the post directly
https://graph.facebook.com/125909647492772_502
summary=true
is what you are looking for
Get likes count :
114916098537132_1265715836790480/likes?summary=true
Get comments count
114916098537132_1265715836790480/comments?summary=true
Get shares count :
114916098537132_1265715836790480?fields=shares
And last [ combining all 3 ]
114916098537132_1265715836790480?fields=shares,likes.summary(true),comments.summary(true)
Improved version ( add limit(0) to removes list of likes and get only summary ):
114916098537132_1265715836790480?fields=shares,likes.limit(0).summary(true),comments.limit(0).summary(true)