Actually the release date was 2010 not 2012: "Standards were released for mathematics and English language arts on June 2, 2010, with a majority of states adopting the standards in the subsequent months." [1] It was adopted by Washington State in 2011. [2]

Are you implying that his children were subjected to Common Core, or that they couldn't have? by 2011, they were age 9, 12, and 15.

[1] https://en.wikipedia.org/wiki/Common_Core_State_Standards_In...

[2] https://www.seattleschools.org/academics/curriculum/common_c...