Yes, I know it sounds crazy. I put a King’s Kush into a closet that was close to a shower that had mold due to tile that was broken and the mold started growing there.
A month later, I did get bud rot (botrytis) on two plants, then all of the bread we had in the house is getting mold about 3 days after it comes into the house?
I don’t have photos of the bud rot on the plant right now, it did have it and I threw it away, didn’t use it bc of this forum which identified the bud rot.
I can say that I’ve seen it growing on the walls of an old shed with grow lights in it for years and never had an issue. Too high a humidity combined with no air is usually the culprits.
I doubt the mold in your shower is the same as the botrytis. More than likely the high humidity of the location allowed bud rot to set in and take off.
The area may be fully contaminated by spores, (tell me there’s no carpeting). In the future try to keep humidity lower in flower, and keep an eye on rh spikes at lights out.