No it isn't! It's kind of typical of what software looks like in a academic setting, as in where it's not someone's main job and they don't really know what they're doing, but that file is horrendous! Just the length should be a warning, the fact that all the logic is in one place, there's no separation of concerns, there's no testability, the cyclomatic complexity is off the scale.
And what's revealing about the comment I quoted is that it suggests that whoever it is, is just poking at it with changes until it 'seems' to be doing the right thing, which is probably all that is possible because of it's manifold deficiencies, only some of which I referred to above.