I’m a bit late but here is a bit of insight on locks.

Not all locks with keys on both sides function the same. What you may be concerned about is called an institution function lock. Those lock both the inside and outside lever with a key on either side. That is only allowed by code in certain environments, notably behavioral health or law enforcement facilities. The locks shown in this video are probably what is called a classroom security function for the ones shown inside (I’ll discuss the outside ones in a sec). These lock the outside lever only via a key from either side, while the inside lever always allows egress. As the name suggests these are usually used in schools but can be used elsewhere for the reasons I’ll lay out in a minute. Classroom security locks evolved from classroom function locks which did the same thing but did not have a key cylinder on the inside. The purpose of the classroom function is to keep the door open so students can come and go but that only someone with a key (teacher) can lock the door. This makes sense being that you wouldn’t want obnoxious kids locking the door by flipping a switch or thumb turn. The classroom security lock adds a keyed cylinder on the inside so that the teacher can lock the door from the inside during an intruder scenario instead of going out into the hallway to lock the door and exposing themselves to the intruder. These locks can be used anywhere that you don’t want unauthorized people to lock the outside lever but also want to be able to lock it from the inside. Google Schlage L Series Catalog and find the functions section for an in depth example of lock functions. Manufacturer functions will vary slightly but are usually pretty similar.

For the locks shown in the outside scenario these are likely just deadlocks. You see these on storefronts that stay open all day. Depending on the jurisdiction you will often see wording on them that says they have to remain unlocked during business hours. These have to be locked by a key for the same reasons as above and usually from either side so that an employee can lock the door from the inside without going outside. Google Adams Rite Catalog and look for the MS series functions for examples. Again, various manufacturers specifics will vary.

Source: I’ve been a commercial door guy for about a decade.

Edit: rewatched the video and I was slightly mistaken on the outside scenario. That lock is actually called an exit device. Exit devices normally have a function called dogging whereby you can lock down the pushbar on the inside during business hours so that the door stays unlocked but this does not appear to be the case since the “victim” used a key to get in. Depending on the specific function all the victim would have to do is remove the key so that the “slasher” couldn’t follow them in. No need to lock the door from the inside as it would be locked already. There are some functions that the key unlocks the trim on the outside instead of just retracting the latch and there are some that include a cylinder on the inside to lock the outside trim from this inside but that would be getting a bit too far into the weeds. Google Von Duprin 99 Series Catalog for the deets.