Sturgis's "Last Days of Dublin Castle" records "The Dublin Corps Elite of the IRA have celebrated he release of de Valera by murdering in Grafton Street this evening two Auxiliaries from F Coy quartered here - both out shopping unarmed and in mufti"
Two Auxiliaries (Cadet Leonard Appleford and Cadet George Gerald Warnes) are shot dead on Grafton St. near Chatham St by men from the 2nd Battalion, Dublin Brigade, IRA. They were repeatedly shot by IRA gunmen who attacked them off duty. This was said to be part of a larger IRA operation.. The IRA's intention was to encircle Grafton St and shoot all the Crown Forces they found within that area. To many of the IRA groups were stopped by British forces as they approached the area, and the plan was aborted. However 2 Ira men who had managed to get to Grafton St, recognised the two Auxiliaries and shot them
Ned Kelliher's WS says that just 2 of them, he and Rigney, shot Appleby and Waring in Grafton St .
Certainly I doubt if the "official version" is correct. The operation was called off, on that a great many WS agree. It appears to have been a spur of the moment thing by Kelliher and Rigney, who recognised the ADRIC men and shot them.