The solution to this is straightforward: any changes to the votes must also change the hash of the block, which will prevent the network from thinking these two blocks are the same. Next week we will begin testing code to fix this issue. This will include setting up hundreds of daemons and several more pools on testnet to better simulate mainnet. Barring any new issues, we should be ready to launch in 2-3 weeks.
Why is it necessary to delay by 2-3 weeks if the solution is so simple? I appreciate caution, up to a certain point, but I'm wondering if Evan isn't being a little too cautious here.
To give plenty of time for testing. If all goes better than expected, they can always move the date forward like they did when they moved RC3 from the 27th to the 20th. Better than underestimating and having to put the date back.