They're certainly one of the brightest breeds of dog and there's no mistake.
We can't say for a fact that they think in the same way we do, but this one definitely knew there was something wrong with one of her 'flock' and went in search of help...they seem to instinctively know what their job is and I find their intelligence amazing, and they are easily as intelligent as a human child.
I doubt there was any immediate threat to the old bird, but she may have had underlying health conditions and if the weather had changed, she could have been in real danger.
Give that doggy a plate of sausages, and, if I know collies, a tin of sardines into the bargain.
I'd say there's a good chance the dog saved her life. 75 year old woman? - trapped in prickly brambles, what if it went dark, then rained? - we'll never know - thank god, but it could have been horrible for her family had this dog not done what it did.