Bit one sided to be honest. The only real risk was to the three RUC officers and part of the SAS group who were at the rear and the other end of the building and or/behind the blast wall. There was a low wall in front of the station that effectively prevented the ASU from getting the digger much closer to the station beyond the gate. The only reason there was anyone in the station anyway was essentially as a way around the Yellow Card, as anyone attacking the station could be said to represent a threat to those inside. As it happens a couple were slightly injured when the bomb demolished part of the station. It was a fucking big bomb after all.
The main killer group with the 2 X GPMGs were stationed up the road in a copse. Once the twats got out to fire their shots at the station it was really game over, as they were right in the middle of the killing ground. Save for the poor innocent sod who got caught in the firefight, it's pretty much a textbook ambush.
Only two of the group survived and they were the scouts that had preceded the rest recceing the village. I read an interview made 30 years on in the Irish Times and one of them claimed that they had driven back towards the station after it all kicked off, with a view to picking up any survivors but claims that they were stopped by the SAS cut off group. He also claimed that they were later stopped at an RUC VCP but inexplicably allowed to go. Who knows?