Hi mate,
In my opinion, the soil looks overwatered (too wet) for a seedling. The seedlings in general don't need that much water, and the soil needs access to oxygen. I'd suggest your buddy wait until the soil dries out before watering again. Don't forget that seedlings are just baby plants, and as other baby living beings, they do need just enough nutrition (water included) to grow vigorously. Keep the soil moist but never that much as I can see from the pictures. Of course it could be another problem, but the one I'm telling you looks like a major problem. I hope it gets better soon. Peace!