I've never had problems with asking for a hand inspection. I put the film in a Ziplock bag and ask the TSA agent for a hand inspection. They have always agreed, but I'm sure there are some who may want it to go through the scanner. Film is part of the TSA regulations, thus all agents get training on the policy.
TSA is a US agency. How other countries do things is their perogative. As I stated earlier, my decades of experience with international travel thru London's Heathrow is an example of their NOT even paying attention to traveller requests...they take the bag of film from you, and then put it through anyway. Since OP is from New Zealand, it is especially apropos that they know what is done or not done elsewhere.






