The problem wasn't with the manufacturing, it was with the name. Apple has had the entire team scanning through dictionaries and thesauruses, consulting with scientists, being coached by trained linguists, all to make sure that instead of calling them 'rubber' bands they are 'fluoroelastomer' bands.
Y'know, it's a real thing.
From Wikipedia:
A fluoroelastomer is a special purpose fluorocarbon-based synthetic rubber. It has wide chemical resistance and superior performance, especially in high temperature application in different media.
In other words: it's not rubber.