No reason why a Nirod pilot would not hear the seeker's growl.
Sidewinder was designed to be a simple fit, the first AAM not requiring stacks of equipment inside the aircraft.
Nimrod's operated far out to sea, watching for Agentinian ships and subs, and carrying out ESM, communications relay, and dropping supplies to RN ships.
A Pucara wouldn't get near, nor a chopper.
Pucara's were mostly destroyed on the ground, including a bunch in a classic old-style SAS raid over a week before the main British landings.
Some later attacked British troops, and were generally seen off with small arms fire and Blowpipe shoulder-fired SAM's.
A Pucara once attacked an SAS patrol, unfortunately for the aircraft they had a Stinger, and shot it down.
One was also thought to be hit by 30mm cannon fire from a Scimitar armoured vehicle.
I think at least two were shot down by Harriers.
Two Pucara's did shoot down an Army Scout light helicopter.
Many were left after the surrender, some were brought back as trophies, one was restored to flying condition in 1983/84 for a short evaluation by the Royal Aircraft Establishment.
One Argentine B707 on a recce mission looking for British ships, was attacked by Sea Dart SAM's from RN ships, luckily for the 707 crew they were just outside the missiles range. But it was the last time they tried that.
Later the Argentines used a very high-flying Learjet, fitted with survey equipment for recce, it was shot down by a Sea Dart.
If a Nimrod, while on patrol, had encountered any similar Argentine recce assets, they would have attacked.
Sure they probably wouldn't have stood a chance against a Mirage or Skyhawk, but they were well away from them.