The problem with this movie is that it doesn't ring true on either an emotional scale or a rational one.
The key to a good twist ending is that the ending allows everything to make sense. For instance, you can watch the end of "The Sixth Sense," and suddenly you realize why everyone behaves the way they do. Unfortunately, instead of allowing the story to make more sense hindsight, the "twist" ending in BLM refuses to stand up to any sort of scrutiny whatsoever.
But the greatest flaw in "Bobby Loves Mangos" is the fact that all reasonability seems to be sacrificed for the sake of a catchy title.
Spoilers:
The ending revelation that the title refers to is the fact that Bobby isn't allergic to mangos, even though the tape says that he is. Now, this sound like a relatively HUGE flaw in his father's plan, now doesn't this? I mean, assuming that they behave as normal and give Bobby a mango, his whole scam is blown wide open, and they send cops searching for him and the alternate route.
But wait. The plan works, because the idiotic secretary decides to conveniently buy out all the mangos, thus preventing them from ever proving the tape to be the fraud that it is. She does this because she doesn't want Bobby to get sick, like the tape says that he will. Even though, according to that same tape, Bobby getting sick is the only thing that'll save his life. And even though her plan doesn't even make sense, because in all seriousness, there shouldn't be only one fruit vendor in a given city.
Given how the story laid out, there was NO reason for the father to go out of his way to fabricate a story about mango allergies. The ONLY thing that such a fabrication could have done was prove him a fraud. If he needed an excuse of why Bobby was the sole survivor, he could have just insisted he fell off his bicycle or something.
Given how the story is laid out, there was NO reason to reveal that Bobby wasn't actually allergic. What did this actually add? The fact that we now know that the tape is a fake? Nope, Bobby has been kidnapped at that point, so we already know that. The fact that the Principal was a moron for falling for it? No, buying into time travel was what made him a moron, the mango allergy had nothing to do with it.
Seriously, you could take out all the mango references, and the father's plan would have worked just as well. The only thing lost would be the catchy title.
And therein lies the rub. Imagine if "The Shawshank Redemption" decided that "Killer Klowns from The Sahara Desert" would be a more catchy title, and they adjusted the storyline to include a subplot where Andy and Red fight Killer Klowns from the Sahara Desert in order to support the title. It'd suck, right?
Well, so does this "Bobby Loves Mangos."
2 out of 10. It'll keep you guessing til the end, but after that, you got nothing. Worse, you get negative points due to the "twist" ending."