Hi Carl.
I have noticed the same thing in my plant room with certain Ficus. At certain times they will send out roots from the soil into the air (upwards!) and these roots will then drop to the soil, run along the soil surface and often ultimately dig their tips back into the soil. I think this occurs given the right conditions of high atmospheric humidity and a root that was cut or injured, such as with repotting.
This adds another interesting facet to Ficus growth, besides aerial roots etc.
These upward growing roots may be cut off without any damage to the tree or root system. Under the soil surface similar roots are growing that support the tree's health.
Regards,
Jerry "Bonsaihunk"