niknak - John Nott described the French as 'our greatest allies' during the conflict. He clarified this, saying that he should've included the word 'European' before 'allies', but they were in fact terribly helpful.
A nunber of nations who were tempted to provide more Exocet to the Argentines were informed that they would find it impossible to buy spares for their Mirage IIIs and Vs or to have those platforms upgraded at any point in future if they helped out, and proposed transfers of the weapons suddenly ran into unforseen problems. Allegedly...
The only French 'bad guys' in the proceedings appear to have been Aerospatiale, or parts thereof, who are alleged to have forgotten about a small team of technicians helping with Exocet (Mitterand found out and was spectacularly displeased, and the technicians were suddenly remembered and brought home) according to one version of the story - the other is that they were withdrawn as soon as the order to cease helping was given. Also, they were supposedly rather less than helpful in providing the operating parameters of Roland, which might have been useful on occasion.
French Air Force provided DACT with Mirages and provided other useful info. If we're looking for European allies to criticise, the Italians and the Spanish are convenient whipping boys to begin with!