Before you can get your BTC back, you've got to perform burn transaction on the sidechain.
So if the sidechain ceases to function entirely, you have no way to generate the SPV proof that lets you claim your BTC.
But does the paper state that you have to perform this burn to get back or is that your interpretation of what has to happen?
Reason I ask is that many people seem to believe they can get back no matter what.
Are the sidechains "rules" not set in stone at its creation?
I am of the belief they will be but that fact doesn't stop consumers falling victim to deceit, given 99% of the people (pole stats reviewed @ 55 second into the clip) who will adopt Bitcoin are unaware of the mechanism of inflation and how increasing the supply robs them of value, I don't see this ending well for Bitcoin.