In fact, you can if you come into possession of a device that has a security vulnerability which makes it possible. Such a vulnerability was found some time ago in Trezor, see here -> Trezor&Keepkey - Unfixable Seed Extraction - A practical and reliable attack!, and you obviously forgot that you post in that thread.

Of course it would be best if this security flaw could be fixed (this is not possible), but it can be prevented by adding a passphrase or by using SD card.

it requires a gigantic transaction to be sent first to someone in a trade where you get something else in return (like selling millions of dollars worth of bitcoin and receiving the fiat) then 51% attacking (that costs millions of dollars) to reverse that transaction. but the problem is that someone who has accepted such a huge transaction will demand a lot more confirmation which means the 51% attack cost goes into trillions of dollars range.