I recall wort getting in the bucket of starsan from the chiller hose. I usually keep the hose under the starsan and let it run until the wort clears. Then, move the hose to the fermenter. A few days later there was some mold on the top. Starsan is good in the liquid, but settles down and leaves the upper part watery and susceptible to mold growth if there are sugars present. However, I've never seen mold growth without sugars present.
Cheers,