My recent experience corroborates the loaded dice conspiracy. I get that the developers say that it isn't. I even saw a post somewhere that claimed "why would they take effort to even do that" or something to that effect. But they do have the "karmic dice" option, which leads me to believe they might randomly stack the deck against the party in dice rolls
I'm fairly early in the game. Just hit 4th level. Random encounter with Bandits.
Try #1 went 9 rounds and my party had 3 attack rolls that were over 10. I didn't keep track of the enemy attack rolls, but they did well because it ended in a party wipe.
Try #2, I kept better track of the attack rolls on both sides. My party had one attack roll over 10 (Rogue rolled a 19 on a sneak attack). The bandits only had one attack roll under 15. Try #2 only lasted 5 rounds before total party wipe. My wizard only had so many Magic Missile spells which were the only thing that could hit anything.
So, yeah. While entirely possible within the grand scope of "RNG", it is quite improbable to have one side roll so badly over two different instances of the same battle, while the other side consistently rolls high.
UPDATE: Try #3 was more even. Roughly 50% party rolls > 10 and same for the bandits. Maybe the game realized I had suffered enough punishment and decided to play fair. Ha!