The allegations of Downey’s links to the UDR killings emerged in the long written statement from the judge in the wake of the collapse of the Hyde Park bomb case.
At one point, the judgment says that, as well as being wanted for the Hyde Park murders, “a file in the defendant’s name... was concerned with the murder of two members of the UDR and causing an explosion at Enniskillen”.
Though the document gives the date as August 28, 1972, the bomb attack matching that description had actually taken place three days before that, on August 25.
The dead were Private Jimmy Eames (a post office engineer) and Lance-Corporal Alfred Johnston (a butcher), aged 33 and 32, respectively.
Some of the soldiers in a passing Army vehicle had been injured in the blast as well.
The UDR men were among 197 members of the regiment killed during the Troubles (mostly while off-duty) and scores more were killed after they left.
UUP MLA Tom Elliott, himself an ex-member of the regiment, said the debacle around the letters sent to 180-plus on the runs “clearly harms the potential for prosecution” in cases of UDR deaths.
Mr Elliott, who joined the UDR in 1982 (and left in 2000 after it had become the Royal Irish Regiment) said: “It’s really annoying for us as politicians.
“But for members of those UDR families, for members of the Hyde Park bomb families, it must be just harrowing. I can’t think to explain it any other way.”
The Government had planned to introduce an amnesty-style deal for on the runs, but MPs had opposed it and it was dropped in 2006.
Mr Elliott said that the decision to issue letters anyway (something which continued until 2012) had been “totally underhand”.