You did not do anything "wrong: per se.....
You probably shot 24p in the 29.97 setting....
which is OK if you were editing in 29.97....
If you told the sound guy you were recording
24p then that is the speed he ran at....
What you really wanted to do was shoot
720 24pN...that shoots only the native 24 fps
and will drop right into a 24p timeline....
PS-I looked at your website and you have done
some great work....