the burden of proof will likely be on Delta & could conceivably get nasty (& expensive... similar to an 'audit')
you haven't mentioned the worst of it. when this company resumes trading, and it will because the sec can only suspend for 10 days by law, it will resume trading on the grey sheets. there will be no bid and ask. it will be matched trades only. in order to get off the grey sheets, a new form 15c211 will have to be submitted along with a voucher from an m.m..