I heard 2 stories first hand from a person who is around 35 & it happened with R’Elyashiv during his Eretz Yisrael year (go figure which year lol).
1. It was Erev Succos 2 hours before Yom Tov and he was putting up a string succah & boarding it up with cardboard in order to hold it up in case of wind etc. R’Elyashiv was passing by on the way to Shul when he came across the scene and he stopped. R’Elayshiv asked him “What are you doing?” He replied “Im giving strength to the succah in case of wind/rain.” Without a flinch, R’Elyashiv paskened “Since between Pesach and Succos it’s a ruach sheina metzyua (abnormal wind) in Eretz Yisrael, it’s not necessary to put the cardboard on. Ironically, it rained Hoshana Rabah!
2. Shmini Ateres that year (Simchas Torah for Eretz Yisrael), in the Meah Shearim Shtiebel (R’Elyashiv’s Shul) were 2 minyanim going on at the same time. One was laining V’zos Habracha (Eretz Yisrael) & upstairs was laining Aser T’aser (Chutz L’aretz). The shamash screamed “Tarta D’sasri!” (contradiction). His minyan continued, so the gabbai started hitting bal koreh with his shtreimel! He told the shamash (humorously) “lets go to the Rav!” Then he thought–oops! The both went to R’Elyashiv & he told over the story. Again R’Elyashiv gave a fast psak. He looked up & said firmly “It’s wrong to lain 2 different lainings in 1 shul AND it’s wrong to hit another yid. But such a Tarta D’sasri Hashem loves & I permit you to continue!!!
This was R’Elyashiv zt”l’s gadlus & pashut p’sakim with a vast Torah knowledge!