In which case, in order to submit the form you would scroll down until you see the button, and would therefore have scrolled past all the fields?
It sounds like the form itself had a lot of problems. Either there wasn't enough contrast on the fields to know they existed, or the submit button was located above fields that needed to be saved, which is an inexcusable interface design choice. Also one could argue that there should be form validation as well to alert the user of critical unfilled form fields. Then again, we can't rule out simple user error.
I don't know, it just sounds like a lot of stuff was going on here. I doubt a scroll bar on the side of the webpage would be the critical element that solved all of the problems. I have no problem criticizing Apple, but its hard to put the responsibility of the entire internets' usability problems solely onto their shoulders.