Your durian shake = my buttermilk experience in nyc.
Once when my mouth was burning (from the black pepper and green chillies in one dish) at a Chettinad restaurant in nyc, I ordered buttermilk to quell it (as suggested by the server, I originally asked for yogurt) — it arrived shortly, with chopped green chillies floating on top 
My standard indian buttermilk expectation is lightly salted, maybe even a bit of cumin or black salt. In some places, they add tempering. Apparently at this place, also green chillies. And yet I did think the server should have had the sense to tell the kitchen to leave that out if it was standard, given the reason for the order 
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But, re cuisines vs dishes: I still don’t understand painting any cuisine as “spiciest” based on a few dishes or ingredients.
For example, most Indian food is NOT spicy. There are condiments and sauces that accompany every meal to adjust the spice level if desired: chutneys, pickles, thechas — the words change from region to region. Of course there are also certain dishes that are cooked to be spicy, everyone has heard of some of them (vindaloo!) if not others (Naga pork!)
Yet a generalization to an entire cuisine seems limited / limiting in thought (similarly for Thai food where there’s so much more going in terms of flavor balancing and range than “spicy!”)
I often use (very spicy) Calabrian chile paste in place of Indian chilli-garlic chutney when I don’t have the latter (which is most of the time) — yet the existence and application of Calabrian chiles in some dishes doesn’t generalize Italian cuisine as “spicy”, so why the generalization from ingredient or dish to the entire cuisine for other (mostly eastern) cuisines?
