Why were all of the deposit boxes open in the Bank Heist?

I was hopping between random servers on Crime.Net looking for interesting heists. I happened upon a bank heist and joined in. Once we had drilled into the vault, I discovered that every deposit box was already open.

What could have caused this? Was I playing on a hacked server? I doubt it was an accident, since after completing that heist we went to Jewelry Store and all of the safes were open from the start of the mission.

Based on what you have described, you have found a hacker. However, I'm not able to find any videos of what you have described, exactly, however (most hackers focus on giving themselves infinite money and skill points so they become automatically good at the game).

This is a particularly weird case, since most of the hacks I see online affects one player only (the closest I can find to what you describe is instant opening of deposit boxes, safes, and vaults, by one player only). Perhaps the host somehow edited the map data, or something. It's hard to say.