The only reference to this to my knowledge is in a documentary done many years after the war where many civilian islanders were interviewed and one of the ladies that actually took part in guiding British troops in the middle of the night , mentioned that right after the take over on april 2nd there was one of the top brass of Argetine forces of irish bloodline that acutally put it forward to the high command in the island to line up all british on the shore and gun them down once and for all.
She actually went on to mention his name and that he spoke english fluently but she found out about his intentions thru someone that spoke spanish from the islands who was not suspected to understand what they were talking about as she would serve them their coffee.
Very interesting documentary, also the lady was quite a character how she discribed all the risks they took to ensure the brit forces wouldn't get lost or entangled in minefields. worth the time to watch.