The transformation spell was worded in the spell book as "Mrofsnart;" however, when testing it, Preston uses a different spell entirely: "Doof emoceb."
The Summer Cove Tennis Championship takes place in California, U.S.A., where the loser receives a 2nd-Place Blue Ribbon. Blue Ribbons are awarded to second-placers in Canada. Red is the color of second place in the U.S.A.; Blue Ribbons in the U.S.A. are for first-place winners.
When the Rangers morph into Ninja Master Mode, the regular Ninja Steel Megazord cockpit appears behind them rather than the Dragon Formation's cockpit.
The episode message of training to become superior gets undermined by Preston becoming a master magician after "working hard" in the space of about an hour.
There is no night to differentiate one day from the next between Hayley's lunch break tennis matches.
Though Preston's very thick spell book contains a lot of pages, there are only ten spells inside it, and each spell only takes up one page.
If, as Calvin says, Hayley has been practicing tennis each and every day, aiming for a comeback since last year's defeat, why does she neither immediately nor boldly answer Victor's challenge before the school at large, seemingly put-upon instead?
The "tennis championship" is entirely intramural, since no other schools are involved. It's curious why Summer Cove High School would conduct a tennis championship and offer up a nice trophy when Victor is the only student in the sport. Is Summer Cover THAT isolated? Is Principal Hastings playing favorites? Can she think of no way to involve other (i.e. more) students?
Principal Hastings' rise from the ground (like she's made from one piece of styrofoam) during Victor's handshake is more a matter of levitation than super-strength. It's her subsequent tearing off of Victor's prosthetic arm that's a matter of super-strength (that she doesn't have). The sparking arm suggests that some of Victor's torso is robotic as well (which it isn't).
While it is possible for a school to have a sports team (such as tennis or swimming) with only one student on it, Summer Cove's entire tennis season (without the 24-hours-later newly scheduled rematch) comprises one day. No school anywhere - and certainly not in the state of California - has so short an athletic season.