Man,
The people who stamp on your passport are clerks. They do not have decision right. They just collect all docunemts, stamp ur PP and fill a form for you to order cards. You should not worry about anything. Even you told them that you are illegal immigrant, they could not deny anything.
Think what if CIS found some I94 are missing. CIS has record that how many I94 issued to you. Call you attorney now and said you do not know should turn in all I94.
Remember no need to cheat. If you do want to chect, pls ask somebody first to see what risk it is.