Before I would get too excited, the paper could have been used as a backing for an elastomeric seal.
I’m not sure what an elastomeric seal is but it sounds like you might be right. They have been covering this on local radio today and it was apparently used up against a water stop. The preferred material is apparently a rubber sponge and from my understanding the paper was used in 3 expansion joints. Now that is what the corp is saying and I certainly am not vouching for what they are saying.
An elastomeric seal used to conceal dynamite that was placed inside at the orders of Halliburton CEO Dick Cheney, which would detonate right after Karl Rove used his weather machine to direct a hurricane towards New Orleans.
Would an expansion joint be expected to be water tight?