lol! I get your meaning, but that's not my thinking - that'd be a normal fork. What blocktrades and gandalf pulled off was not a normal fork
On Chain1: do maths on steem balance to start ledger of new asset (still on steem). steem witnesses cannot "see" the new asset, so it's ignored and would probably just die off from consensus after a few blocks
On Chain2: fork as normal, but instead of assuming the asset steem uses, it assumes the new asset calculated on the block before it
not a lot of margin for error in that process. Quite possibly the fastest airdrop that's ever happened :D
gtg, bt, et al are frickin' mad men