Yes but if it's over watering there would probably be other problems like root rot.That makes your plant fall over and is pretty obvious.Only water when it needs it(first 2-3 inches of soil should be dry).
Depending on the strain and the stem structure ,the lower fan leaves can turn yellow and fall off it's totally normal.
My Blue Moonshine just did this.Now that the leaves are gone there is plenty of light getting to the lower buds on the bottom branches.See what I mean.Sativa is bigger and lankier and the squat little indica's get all bunched up, it's only natural to make room for light to survive and reproduce.