OP is flying UA which is a US carrier and subject to specific US law (rules) which prohibit exactly what NH did for you.
While it seems like good customer service, under no circumstances should a carrier's employees, including FA's, be handling passenger medications in non-emergent situations, nor should these medications be stored in food containers, even if they are separated by bags and other devices.
There are good safety reasons for this from the perspective of the individual affected passenger, other passengers, and crew.