No

How do you know?

One of my games broke once and I was left with only the sound track and maybe art work 😵‍💫

a

With bad data reads you get either scrambled data or zeros. Both can either make your game glitchy or freeze, to get you to the ending movie your game has to get specific commands and data sequence that's impossible to get due to bad disc read

This isn't possible. A bad disc read will result in incomplete data, not to mention most disc games now a days are nothing but "keys" to play the digital version.

Even if the full game is on the disc, a bad disc read will corrupt a save file, remove your soundtrack, make thins look derpy or stop the game running.

Someone spoiled something, or is about to, aren't/didn't they?

I am not so sure... OP did ask about en ending movie, not a scene or some boss backed by code.

Movies are often stored as separate, regular movie tracks, and the code "plays" them at the right moment. IMHO, it would be possible for a DVD reader to mis-read a game DVD and play a random movie out of it. Back in my pirate days, a badly burned disc would sometime result in random FMV sequences or soundtracks being played when the disc was inserted.

Thanks