My take on the whole RNG thing is based on personal observations and could be completely wrong, but here's what I think:

I believe the RNG implementation is sub par. Technically it's a 50% chance for something, but practically it depends on a seed value and to me it seems there are periods where RNG spread is biased. Even though the majority of players will dismiss this, I've observed similar behavior in other RNG based games.
I've done huge amounts of 2k rolls on Aigis and there are periods where barely any silvers drop, which is normal. There are, however, significantly long periods when silvers drop more often. To some this may not proof of anything and just be good or bad "luck". To me it means that there is a dependency that shouldn't typically exist in a well implemented RNG.

I realize that this will probably stir up some controversy, but that's not really my goal. I'm merely providing a point of view. In the end everyone should always try to learn more, and maybe even provide the rest of us with a definitive answer backed up by solid facts.