The only DVD version of the game that does not require an online connection to complete downloading the game is a unique version that was made available to Kickstarter backers who asked for it by special order (and it only arrived rather recently). My understanding for the reason why this is the case is due to Larian's wish to have the day one patch available for anyone buying the DVD. If the DVD was truly standalone, then the version of the game burned into the disk would have been significantly dated on the day of release. Being a small studio, it makes more sense for Larian to use standard clients like Steam to handle the patching rather than creating their own infrastructure to duplicate it for non-steam versions.
