I found this recently and haven't had much time to study but I have found that the values all have a corresponding OEIS sequence. How might this help in disproving the original statement?
Background and motivation A resolution one way or another to the original question could help to resolve a couple of (presumably not so important) but pesky open problems in number theory. I am preparing a website that I will link to eventually that will give the full background. However, it is too lengthy for this post and in accordance with advice from META MO I will omit it to keep this as brief as possible. Additionally I am not a research level mathematician so please forgive any unintended ignorance when responding to comments.
Important update
Going back and looking at the background of where this comes from. I found that what I am asking for is equivalent to this,
$$\frac{\left(c_{1}-x_{1}\right)\left(c_{1}+x_{1}\right)}{c_{1}^2}+\frac{\left(c_{2}-x_{2}\right)\left(c_{2}+x_{2}\right)}{c_{2}^2}=\frac{\left(c_{3}-x_{3}\right)\left(c_{3}+x_{3}\right)}{c_{3}^2}$$
Where $c_n$ is the associated hypotenuse of the primitive triple and $x_n$ is an integer solution to the circle,
$$x^2+y^2=2c^2$$
I wanted to mention this connection as it is related to the solution set mentioned by Constantin-Nicolae Beli.