Theory: Larry was Slacking Off at the Tangerino Grill

Abstract
Larry was slacking off at the Tangerino Grill before he hijacked the Sunset Express in Paper Mario: Color Splash.

Arguments

 * Argument 1: Larry is lazy, slacking off is in his character. We've seen him slack off before in Mario and Luigi: Paper Jam when Roy was calling for him to help with Mario, Luigi and Paper Mario, and when Wendy questions where he's at, Roy says he's probably off playing video games (simply playing in the Japanese version I think, unspecified with what, I'll have to get proper translations for the Paper Jam JP quotes) Wendy replies with "Ugh, it figures" both of which shows that they expected that from him. Let alone he admitted he wasn't gonna try very hard when helping Captain Goomba look for Bowser in Minion Quest: The Search for Bowser.


 * Argument 2: Larry was the only Koopaling besides Roy who didn't already have his Big Paint Star by the time he has to fight Mario, and the only reason Roy didn't already have a Big Paint Star was because Roy didn't have to get a Big Paint Star. Morton was the first Koopaling and we see him actively looking for his Big Paint Star, and he eventually gets it by the time he has to fight Mario. Larry was the fifth Koopaling and yet when we first see him, he is behind curtains asking for the perfect steak to be cooked, and he doesn't order his minions to hijack the Sunset Express until after he heard Mario was headed to Starlight Cape, so I think he realized he didn't do his job and got his minions to hijack the Sunset Express so he can beat Mario there. In the Japanese version, the first thing Larry says is something along the lines of "Hey Mario. I, You caught up with me? Not bad. Why don't you catch up at the restaurant a little more? I'm so harried I wanted to take a rest." (I'll have to get proper translation of that quote too) and not only did he want to rest and Mario showed up too soon for him, but based on Wendy's dialogue, she was apparently waiting for days in that clam shell, so not only did Larry have more time than Morton, Iggy, Ludwig and Wendy, but he also had multiple days to get his Big Paint Star but didn't. Also speaking of Larry's Japanese quote, the definition of "harried" is to feel strained as a result of being persistently demanded/harassed to do things, as in, he's harried because Bowser wanted him to get the Big Paint Star and he just wanted to relax instead, because he's lazy why wouldn't he want to relax, or at least that's what it seems like.


 * Argument 3: It doesn't really seem like something Bowser would order Larry to do (under any circumstance) to go hang out at a restaurant as the VIP customer and ask for the perfect steak to be cooked for him, especially if Bowser is being controlled by the black paint. Peach said that Bowser didn't seem like himself and I think it's safe to assume that Bowser was acting meaner than his usual self, which makes the chances of Bowser ordering Larry to go ask for steak lower than it already was before. Bowser also became meaner from what looked like black paint in Bowser's Fury which would support the idea of him being possessed by black paint making the chances he'd order Larry to do something like that lower.