Can you be more specific? If you have a partial piece of data (say because the data was streaming and a rocket exploded), the parser for that data is unlikely to work out of the box. Hence the use of a hex editor.
IDK, that tweet felt like when you're watching a movie and then the 'hacker' comes around and you see a lot of props on the screen that are designed to excite 'geeks'. Like, right now, a lot of guys should be like: "OMG OMG! They are looking at the hex code directly! Damn, that is so looooooow-level, they call it rocket science for a reason!"
Anyway, hopefully they find the problem; whether with hex editors or not SpaceX is really doing cool stuff.
Far from BS, pointing a hex editor at your data dump sounds like the very first thing you'd do when you get some data that your software can't immediately read.