Actually I will believe it, because Pokémon capture rates function entirely on a random number generator. Catching a legendary in one attempt isn't even close to being hard to believe. Unlikely, yes, but very capable of happening. But you're still not a man until you catch it with a Love Ball.
I remember one time I managed to capture a Groudon using a simple Pokeball on my very first toss. That is not something I'd be able to repeat, but it was awesome nonetheless. Wait till you see Zygarde, it's one heck of a let down for being the third legendary of the generation
Really? Did they change it for Gen VI? It was my understanding that every Pokemon has its own catch rate which can then be plugged into a formula along with a bunch of other factors like status ailments, percentage of max HP remaining, and the kind of ball you use.
It's always been the case. What you said is true, yes, but ultimately what decides whether or not a Pokémon is caught is the RNG. Which is why even if you fight the exact same Pokémon twice, it can be easy to catch one time, and difficult the next. It's entirely down to what the game decides to give you each time you throw a ball.
