In all my daily open carrying when I lived in DE, not once was I detained, thrown to the ground, or anything. I have passed by LEO's who saw me carrying and they said nothing (or gave me the "nod".) I have also been pulled over by the police twice, with my gun on the passenger seat, and again, not once was my gun ever mentioned. Heck, even after my self-defense shooting incident where I used my gun on someone, never was I thrown to the ground or harassed or anything. Not even cuffed when the police came to my house. No problems there.
I've called the AG's Office before, with similar questions, and was "discouraged" from OC as well, but not with such extreme threats of being thrown to the ground or needing a lawyer and a hefty wallet for court issues.
I believe you just got the wrong person at the wrong time who projected his own anti-OC agenda onto you. Don't let it worry or discourage you.
Dave
Co-Founder & Global Moderator
Delaware Open Carry
"You have to be prepared to do the violence in order to survive the violence."