You did the right thing by using your torque wrench to 'check' the tightness and you found it out of s
Here is where a lot of guys get into trouble because they mix up, 'Tighten and 'Check''
When an engine is brand new, never run, the head bolts/nuts should be torqued to the recommended value; somewhere in the range of 12 foot pounds. Then they should be 'checked' again after the engine has reached operating temperature the first time. After that they can be 'checked' periodically but not necessarily 'tightened'. Too many guys have made the mistake of thinking they need to see some rotation of the bolt/nut when they 'check' the tightness and that's where they end up twisting off studs or damaging threads. By 'checking' one only needs to apply recommended torque to the bolt/nut. If it doesn't move when applying the 12 ft. pounds then it's tight. It does not need to be tightened more just because they're being 'checked'. Thanks for the post. I hope others read it and like you, learned something today.