I talked with one of sakuga fans who attended the movie screening, the part where the hamburger popped out from the box was presumed to be Ohashi's work. It seems he was responsible for 80% or 90% of food scene in the movie.
"大橋実さんのパートは、ハンバーガーの辺りは、私も映画見た時に、パンが押し返す作画に感動し、大橋実さんだろうなと思ってました。新海誠監督の作品の料理パートは大橋実さんが9割？8割関わっていますもんね"

he definitely did post #122687, very reminiscent of his scene in flavors of youth.