i am not familiar with BMW repair procedures so i cannot give you 100% accurate response.
i didn't watch the video. i am assuming we are talking about the roof panel replacement

on a VW and mazda you not only bond the parameter all of the way around the roof you also must use a squeeze type welder that replicates the factory spot welds. this is just for the roof panel only

also with seeing the very first picture this car had significant damage to the center pillars and the ultra high strength reinforcements under the sheetmetal under the roof and side panels. if this is damaged the exterior sheetmetal and the ultra high strength steel reinforcements MUST BE REPLACED.
basically stated by just looking at the first pic of the care in the video pretty much ALL OF THE EXTERIOR sheetmetal must be removed. then the reinforcements that are 1 piece covering the entire side panel must be removed. if you damage the inner bracing that must be replaced also. without looking at the car directly and only seeing the first pic. ALL OF THE PERMANENT SHEETMETAL from the floor of the car to the roof needs to be replaced. just a guess but i would assume the front inner structure was damaged also so that needs to be replaced too.


for a comparison we have a 2016 or 17 VW Tiguan, the last year of the old body style, that someone hit something with the "A" pillar in the middle of the windshield and bent the inner structure about 6" wide. it shattered the drivers door window also.. it also damaged the inner bracing under the dash also. we saw this when we removed the windshield.
the proper repair procedures is to completely replace the entire side of the car including the 1/4 panel. it only comes from the dealer this way in a 20' long box. this must be done to replace the 1 piece ultra high strength steel reinforcement, this part also is delivered in a box 20' long. the reinforcement runs from about from where the rear wheel is all of the way to the cowl. because the inner bracing under the dash is bent also the entire shock tower needs to be replaced also. because the bracing is integrated into the roof inner structure the roof and all of the inner structure must be replaced also. to weld in the roof structure we have to replace the rt 1/4 next to the roof panel to weld properly.
i really don't have access to the estimate . but i have heard the estimate is in the $35K range to repair properly. the car is only worth about $15K. this car has been sitting outside with plastic over the removed windshield for about 3 months. there have been multiple people basically saying "you have to be kidding me. it's only damaged here in this small area. can't you just put this small piece in and call it a day?" the shops official response is the car requires this to repair properly.if you don't want it repaired this way take it somewhere else. this isn't open for discussion.