If only the glass would speak out and let us know which direction the water travelled prior to cessation, the question would be answered and it would no longer be unnecessarily analyzed. For if the water was entering the glass and stopped, glass would be half full of water, and if the water was being removed, glass would be half empty.
Please, speak out glass; give us the missing variable, and the others will stop analyzing you.
Let's give glass a break; let it provide the variable so it can finally be at peace without worrying about our analytical nature. No, that doesn't mean break the glass. We're here to resolve the equation that has led to glass' mistreatment; we're not here to destroy glass' physical form.