At least the only issue you may have encountered would be if your pen ran out of ink but at least you could always get another one. The rest of us couldn't get a new website to fill out.
I liked the comment from one forum poster stating it was our own fault for waiting until the night of the census to complete it with the subsequent website issues. Umm, isn't part of the point of it to know how many people were in your house on that night?
There was some encouragement to do it "beforehand" and lodge on the night making alterations as/if necessary.
I don't even think that was possible.