"Not my Fault"

Skyler's latest phrase is, "Not my fault." When Kimberly was younger and would be crying, Skyler would try and go over and comfort her. But most of the time it only made her cry more, so when he'd feel bad that his attempts to make her happy didn't work, we'd tell him that "it wasn't his fault she was crying." Well, a couple months later, now Skyler has learned that he often gets in trouble when Kimberly starts crying (because it often IS his fault). So a week or two ago he started defessively saying, "Not my fault" whenever she starts crying. Whether or not it is his fault or not, it surprised me that he'd already be trying to get himself out of trouble... They sure learn fast!