I think the TSA could change their policies without having to admit they were wrong. They could say something "consistent with the rest of the world, shoe explosives aren't a credible threat and shoes can remain on". Or "The liquid explosive threat isn't as viable as earlier thought, so we are allowing more liquids and larger sizes, such as water bottles". Imagine the good PR they would get by letting people bring a bottle of water through security. We would still be as safe.

On the other hand, after seeing the reaction to allowing small knives on board, I'm not sure if any change the TSA makes will be well received. There are still too many people who will do anything for safety. It would be nice to have some sanity when it comes to the TSA rules. I have a 4 oz bottle of liquid adhesive I use with my insulin pump. I could claim that as a medical liquid or throw it in my quart bag. All it's going to take is one TSA screener who won't listen or be reasonable and I will be forced to toss it. If it was 0.6 oz less, it suddenly isn't a threat.