The motorway was closed - in both directions - until lunchtime as investigators examined the crash scene on the eastboundcarriageway between junctions 25 and 24.
Emergency services were called to the eastboundcarriageway between Margam, near Port Talbot, and Pyle, near Bridgend, after the alert was raised just after 12:30 GMT on Sunday.
Mr McCourt, from Sandwell in the West Midlands, was driving his lorry on the eastboundcarriageway of the A45 near Doddington, when a breeze block smashed through his windscreen.
The police watchdog continues to appeal for information from anyone who saw a red Ford Mondeo travelling the wrong direction on the eastboundcarriageway of the M4 near the Christchurch Road motorway bridge at around 0315 BST.