I think in casual speech "equally possible" usually is taken to mean "also possible." I think most people would say "equally likely" to express what you're saying.
For what it’s worth, I am a native English speaker and I disagree with the other poster. I would interpret “equally possible” similarly to how you did.
For what it's worth, to me, "it's equally possible" means "it's also possible, however remotely". I know it doesn't make sense, but, then again, neither does "I could care less".
The word equally possible implies equal chances for me. Otherwise it is equally possible, that the evidence was in fact planted by aliens.