yeah. unlike an arbitrary garbage pointer, a null pointer is something the callee could detect. but on linux or windows the operating system will reliably detect it for you, and in a way that makes it a lot easier to debug: it segfaults, making it obvious that there's a bug, and your debugger will show you the stack trace leading up to the LoadFileData call with the null pointer parameter. and, as you point out in your other comment, in the very next line after your call to LoadFileData, you need the data size, and if you passed in a statically null pointer, you don't have it, so you realize you're going to need to pass in a pointer to an actual int

so, while the documentation could and should be more explicit than the single telegraphic line you quote, the function's behavior is fine, and detecting and trying to handle the null pointer would make its behavior worse and harder to debug (except on like an arduino or ms-dos or something)

not every c api description needs to be an introductory tutorial for c