Plot hole: After Rita kills Billy, why didn't any of the other rangers do something to help him? They could have very easily done CPR on him or at least called for an ambulance.
Suggested correction: (1) they did...they took him to Zordon. (2) These are high school kids. Have you ever seen any slasher flick before? Not every HS kid knows CPR.
Every high school lifeguard that ever existed.
Suggested correction: They may have not been in range with cellphone towers to get a good enough signal. Also, they had superpowers including super strength so doing CPR on Billy would have been very dangerous and would have probably hurt him even more.
Plot hole: The world depicted features magic, an evil overlord who 2,000 years before tried to conquer the world, and several races. Despite these HUGE differences with our world, everything turns out of the same as our world, with nations as they are now, and a casual mention of the Alamo and "Mexicans still getting shit" for it. So our current history has not been altered a single bit by wizards, dragons and super-strong races roaming the Earth. Fine. In this ungodly implausible context, orcs live with humans in cities that mirror ours; humans and elves don't trust them, but still they live in towns with them, they go to schools, run businesses, half of the NFL is formed by orcs. Even the movie Shrek exists! And yet, at the end of the movie Nick Jakoby becomes the first Orkish police officer in the USA! There is just no way a society like this, mirroring closely our own and with orcs that existed as long as humans did, can exist with no orc ever been part of law enforcement.