The fork was at the block level not transaction level.
The transactions are on both chains. While they may be in v0.8 blocks and still unconfirmed in the v0.7 fork they do exist in the v0.7 fork. The only transactions which couldn't exist in the v0.7 fork are those generated in "v0.8 only blocks" and those are hard locked by the protocol for 100 blocks.
Had both halves of the fork existed for more than 100 blocks that would have presented a more serious problem. This is why the stakeholders (exchanges, merchants, miners, and developers) moved quickly to halt transactions, warn users, and move to the v0.7 version of the chain BEFORE one chain got more than 100 blocks from the fork point.
The transactions are on both chains. While they may be in v0.8 blocks and still unconfirmed in the v0.7 fork they do exist in the v0.7 fork. The only transactions which couldn't exist in the v0.7 fork are those generated in "v0.8 only blocks" and those are hard locked by the protocol for 100 blocks.
Had both halves of the fork existed for more than 100 blocks that would have presented a more serious problem. This is why the stakeholders (exchanges, merchants, miners, and developers) moved quickly to halt transactions, warn users, and move to the v0.7 version of the chain BEFORE one chain got more than 100 blocks from the fork point.