Dr Adeley referred the matter back to the Director of Public Prosecutions to consider prosecuting driver David Harwood for gross negligence manslaughter.
The shock development came after hours of legal discussions on day five of the hearing at County Hall in Preston.
It followed an application from the teenager’s family for the matter to be reinvestigated in the light of new evidence which came to light this week.
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The original Crown Court case against Harwood collapsed three years ago on a charge of causing death my dangerous driving.
Dylan’s family has since been campaigning to get the matter reinvestigated.
After hearing the news Dylan’s mother Tracey Milligan hugged friends and relatives and said: “I am very happy. Let’s get him back for a proper investigation.
“All I have wanted all along has been the truth. This case was handled terribly and the Coroner Dr Adeley has gone above and beyond. He arranged a reconstruction and that has been a godsend.
“This week has been horrendous sitting through all the evidence. We will now wait and hope that the police do a good, thorough reinvestigation and no stone is left unturned.
"They (the police) did a terrible job. I think we have gathered that by the evidence which has been given this week.
“I am not going to comment on why. We have to think about going forward and getting the right answers and the right result for an innocent 15-year-old boy who was killed and left.
“I don’t want any other family to go through what we have gone through. That was always my intention.”
Dr Adeley handed the case back to the police for a reinvestigation.
He told the inquest: “It could take months, even 12 months”, before a decision could be made by the DPP about a possible new trial.
He explained that an application had been made by the family under the Coroner’s Inquest Rules and that he had to adjourn the inquest and notify the DPP.
He said that the reconstruction ordered by him had “provided considerable new evidence and insight into the case.
“Therefore I will adjourn the inquest and notify the DPP that he should reconsider the prosecution of David Harwood for gross negligence manslaughter.
“It will take time for the police to complete the enquiries they will need.”
Lawyer Sefton Kwasnik, representing Dylan’s family told the inquest: “We would be more than comfortable in meeting with the police on this matter.
“It is a very prominent case and if there is thought to be any iota of help we can offer we will.”
Mr Kwasnik also paid tribute to the Lancashire Post for the way it had handled reporting of the case this week.
“I want to thank the press for the very sensitive way they have published the case.
“That maybe what has brought about this outcome today.”