There is no real doubt that the Chicxulub bolide impact occurred, caused shockwaves and tsunamis, and ejected a bunch of hot material. Eg, quoting https://www.

There is no real doubt that the Chicxulub bolide impact occurred, caused shockwaves and tsunamis, and ejected a bunch of hot material. Eg, quoting https://www.pnas.org/content/pnas/116/17/8190.full.pdf https://www.pnas.org/content/pnas/116/17/8190.full.pdf, "The KPg boundary ... is distinguished by impact-related debris, including a distinctive iridium anomaly, shocked minerals, ejecta spherules, microkrystites, nanodiamonds, and occasionally unaltered impact-melt glass." (That paper is about the amazing Tanis site, where a ∼1.3-m-thick deposit records events which occurred minutes to hours after the impact, and includes pterosaur fossils and perhaps dinosaur feathers and a hip bone. https://en.wikipedia.org/wiki/Tanis_(fossil_site) https://en.wikipedia.org/wiki/Tanis_(fossil_site) ) Even if non-avian dinosaurs were killed off earlier by consequences of the Deccan traps, we know modern snakes survived, so their ancestors must have survived the Chicxulub impact.