I am presently learning Bava Kamma and also preparing for Pesach.
So I asked - If one of the 4 sons is a תם, then where is the מועד??
The only terutz I have is the the Ben Ha-rasha is a מועד!
But remember, the gemara teaches that a מועד can prove his taming of himself and resort back to being a תם - and so can the Ben Harasha turn EVERYTHING around!!!:-)!