Revealing mistake: When Velma is running from the two one eyed skeletons she goes into what looks like a warehouse and the floor is all wet and in some places there are puddles. When the skeletons come they step into a puddle but the water doesn't even splash or ripple. (01:11:20)
Revealing mistake: When Shaggy and Scooby fly off the cliff into the Mystery Machine you can see Daphne and Velma's hair hanging unnaturally towards the left, indicating that the set is on its side so Shaggy and Scooby look like they fly into the van. (00:55:45)
Revealing mistake: Just after the pterodactyl ghost has been "tied up", it flies off. When Shaggy and Scooby are looking at the ropes, Fred and Daphne duck at the same time. Obviously it was meant to look like they are ducking when the pterodactyl's wings flap, but the pterodactyl has already flown off. (00:09:00)
Revealing mistake: When Daphne is attacking the 10,000 Volt Ghost, she falls on the ground besides Fred but it's not on soil. It looks like a mattress. (01:08:10)
Revealing mistake: When Fred rushes in to fight the Black Knight Ghost in Mr. Wickles' castle, he is hit in the face several times with the back of his shield. As he falls, you can see the pad on the back of the shield to protect his face. (It is not noticeable when he first runs in.) (00:23:20)
Answer: The simple answer is money. Although it has to do with film studios and distribution companies releasing American films to the international markets. Because of technology, studios can digitally alter products in the film and can now sell product placement rights more than once. This practice started with "Demolition Man", where in the US, Taco Bell is the only surviving fast food place. But, overseas, the restaurant is Pizza Hut. In "Scooby Doo 2", Burger King purchased the product placement rights for the film along with "right of first refusal." Burger King then decided to just focus on the U.S. plug. Warner Bros. Was free to sell the plug for the international market release, which KFC bought. So the DVD version was the domestic release version and the Netflix version is the international release. But, I do not have an answer to "why is Netflix showing the international release version?", but I'm sure it has to do with cost of purchasing the rights to stream, unless KFC also bought the product placement rights for streaming in all markets.
Bishop73