Bearing in mind that this is a soap its perfectly feasible that the body is not Callum. David dumps body of Callum whom he presumes is dead. Callum wakes up in hole in Gails boudoir. Crawls out of hole and kills one of his druggie pals and dumps him in hole along with his plastic card. If the body is badly decomposed there may not be any prints but DNA identification will prove who it actually is. No mention has been made of this by the polis who of course are stilll at the scene
Love many, trust few, always paddle your own canoe