My grandad Henry Dale told me my great grandad, who is also called Henry Dale, is buried in an unmarked grave at Audley. When he was alive he told me that it was the Miners Union who wanted to get the bodies out of the pit, the NCB wanted to seal the pit and have it as a grave for all the miners. My grandad identified his father's body by his clothing and moustache.
In answer to your query regarding the pit being sealed. It had to be temporarily and numerous stoppings were erected to prevent further explosions. It was thought that gob stink from a fire in the goaf killed many of the victims...I.e. Carbon monoxide mainly.
A list of those killed is first...including H Dale aged 54.
He is shown in a further list later as number 126 body Henry Dale, 54 his job described as a shifter, lamp number 483.
However according to the HMI report the gruesome recovery of the dead continued until halfway through the following year and the last body was recovered on August 1919 some 20 months after the explosion.
Open up Podmore Hall, Minnie Pit - Durham Mining Museum - Colliery disaster. There are several other reports and newspaper reports in great depth answering all your queries and dispelling some of your fears.