Destruction was arguably stronger than affliction (and demonology, for that matter) on many fights this tier though in contrast with the last one.
This is especially true with relatively low gear and pre-LMG where destruction had a very competitive mono-target DPS, and even though the fight it really shines mostly have strong cleave/AoE opportunities, I feel (I insist, feel) like most of the added damage is useful damage most of the time (i.e. less overkill & useful cleave).
My warlock guidmates and I have been jumping around specs this tier and, a posteriori, here are the fights I would really recommend going destro to someone tackling them on HC (my experience is on 25H though, ymmv !):
- Tortos (especially if you are kiting bats, but very strong even then. except if your raids the aff 70% slow on turtles)
- Megaera (especially if your raid can use the RoF "passive" AoE DPS)
- Durumu (especially if your raid is lacking wall DPS)
- Primordius (though the benefits of different specs very much depend on your strategy on this fight)
Of course it's not to say it's not viable on the others (as a matter of fact, I was destro on several additional fights at the beginning of the tier), but these the ones I feel destro is noticably superior or more useful to the raid than aff/demo.