The doorbell makes no sense
We see Ed Rooney ring the doorbell by just HOLDING HIS FINGER in it for a long time.
However, the sound does not conform to this movement - again the 'visuals don't match audio'-syndrome, that's so common.
We hear two separate 'ding dong'-sounds, which would still be almost fine (although usually, that's not how doorbells work - the FIRST sound, 'ding', usually happens when you push your finger into the doorbell button, and the SECOND sound, 'dong', is heard when you release your finger from the doorbell button, so you can pace and rhythm it in any way you like), but..
BUT!!
.. he just KEEPS that finger pressed (or is it depressed? Do fingers have mental health problems?), and during the duration of the push, we hear FOUR sounds.
Even that would be fine (sort of), but there's inconsistency with the rhythm. First 'ding dong' is faster, then we hear a pause between the second 'ding' and the second 'dong'.
It's like.. 'dingdong dinnnngg........... donnnnng'.
WHY would this happen just by KEEPING THE FINGER (de)PRESSED?!
WHY?!
(To add, that's all we hear although he keeps the finger there a bit longer - we should KEEP HEARING CONSISTENT DINDONGS THE VERY LEAST, BUT WE DON'T!! It's like the doorbell is programmed to give you exactly FOUR sounds and no more, there's NO WAY a doorbell would EVER work this way!)
It makes no god damn sense unless some idiot made a mistake in the movie!
Whose doorbell works like that? Hands up? Bueller? Not even Bueller's doorbell should work that way, this is movie-cheating and destroys the immersion immediately!
I hate when people ruin good movies this way. Why can't it be a normal doorbell, where the 'ding'-sound happens when you PUSH the button and 'dong'-sound when you release, and why can't Ed Rooney keep PUSHING and releasing and the sound happen accordingly?
It wouldn't have been THAT DIFFICULT to make considering all the things done in the movie!
What a NONSENSICAL DOORBELL!
Just to add - there's NO WAY that Ferris' taped reply would happen so quickly and instantly - the system would have to know to rewind the tape, and start playing it again, as well as activate the door microphone immediately after Ed releases the button. HOW can it be this fast and immediate with THIS technology?? There'd be at least SOME kind of pause.
I hope I don't have to make the typical disclaimers about how I love this movie anyway due to its marvellous 1980s energy, great musics, charismatic performances, their amazing house (well, from poor entity's perspective anyway), and the rebellious, quirky theme of making ditching school seem like a HEROIC ACT in the world of dull adults and businesslike corporate institutions and robotic students.
A bit of freedom is what we all want and need, many of have just forgotten it, and this movie reminds us of that.
BTW, why didn't Ferris just use the dog flap to get in the house? It's clearly big enough for Rooney, so Ferris should have no problems. Why would you even need or HAVE a key for the backdoor, with such an ENORMOUS, huge dog flap?
Ed rooney clearly doesn't understand dog psychology at all - imagine what Cesar Millan could've done with their labrador...it would be just laying in the corner, all relaxed, while the principal freely explores the house... unlawfully.
I can't imagine how a principal is willing to break the law and enter someone's house without the owner's consent, and then attack and injure their dog as well, and no one even tries to get him fired for that or press charges or whatnot. This guy should be in prison instead of eating yummy gummybears in a school bus.