Following the collapse of the 1973 ceasefire Mitchell became embroiled in a Loyalist feud that would ultimately see him imprisoned. The roots of the feud lay in the Ulster Workers' Council strike when a brawl between members of the UVF and the Ulster Defence Association at a bar in the Tiger's Bay area of north Belfast saw UVF member Joe Shaw killed by a shotgun in what both groups initially agreed was a "tragic accident". However tensions were stoked by the UDA claiming the Dublin and Monaghan bombings, which had actually been a UVF attack, and drunken fights between members of the rival organisations became common, culminating on 21 February 1975 when east Belfast UDA man Robert Thompson was stabbed and killed in one such brawl. The feud reached a zenith on 7 April when Hugh McVeigh and David Douglas, the UDA members identified by an internal UVF inquiry as responsible for Shaw's death, were abducted and taken to the British Legion Club in Carrickfergus where they were severely beaten. From there they were taken to a clifftop spot at Islandmagee where they were forced to dig two graves before being shot dead and their bodies buried in them. It was five months before the bodies were discovered.