Bird died mysteriously until we found out what might have been the cause, could this be it?

So for mothers day we got my mom a pair of parakeets that were on special at petco, one survived while the other died. We made jokes that one killed the other cause they got in a fight over who's colors are better. But we had to throw him out. We didn't inspect the body because that is germ city and birds are infamously known for flu and other types of diseases. So the other day I do this on a normal sunny day in california basis, I hang my bird in the front of my house. So I am chilling waiting for my dog to pee since I took him out to pee on the grass cause he was whinning. And A FREAKING OVER SIZED fatty cat comes falling out of a tree and i'm like you MOTHER-F word and I chased it down. Keep in mind I hate cats, especially strays. So this made me angry as hell. Me and my look each other in the eyes and said now we know what killed our bird. Cats are smart and I wouldn't doubt that one of them tried to kill the bird or open the cage but couldn't so he shook it or scratched the cage and harmed my bird therefore leading to his death. Sadly I can't take out my bird until later when my backyard trees come out and my puppy protects it. ;) but I was wondering if there is no sign or entry or the birds being loose is possible a cat could of shook/scratched and clawed my bird to death?