> Ordinarily, the blockchain would resolve this by including only the first transaction in the block, but the attacker was able to reverse transactions since they had majority control of the network.

Not a very precise explanation, just checking, what exactly does this mean?

I always thought the way a 51% double-spend attack worked was by broadcasting a transaction for human consumption (eg, I'll give you Y coins for Z dollars), then secretly mining your own blockchain for the N successive chains following it. After the humans have completed the human-level transactions after waiting the standard N successive blocks with no transaction conflicts, you release your own secret blockchain fork back into the public with data that contradicts the current popular one and instruct your network to ignore the competing publicly-acceptable chain. The new private one wins so long as it is equally as long as the public one which it should be because you have more compute power than the rest of the public.

Is that basically what happened here?