This kinda stuff happens a lot with my
plants that require lotsa water. What happens is that the soil has compacted. Imagaine a pile of rocks. When you shake the pile of rocks, it settles. Well that's what's happened with the soil. Its all settled, and stuff. Below the surface, the water is still being retained, so don't worry. What your friend can do is water the
plant until water comes out the bottom. Then let it drain, until it stops. That should be enough for most
plants.
It happens to my bird of paradice, mystery
plant, and my rubber
plant a lot, and they need to be kept moist. So i don't think its any real cause for alarm.