You may think that a paracentesis incision is trivial and has little effect on the case, but that is not correct. In this case the paracentesis incision is too wide and is leaks excessively during the surgery and that causes a fluidic imbalance. Remember that there is one source of fluid inflow: the balanced salt solution bag (or bottle) which is forced into the eye with infusion pressure (or gravity with bottle height). There are two sources of fluid outflow: what you aspirate through the phaco tip (the aspiration flow rate) and also the leakage from the incisions. We intentionally have slightly leaky incisions in cataract surgery to cool the phaco needle and avoid a phaco wound burn. But when it leaks too much there is a fluidic imbalance and the anterior chamber becomes unstable. This can cause the posterior capsule to come toward the phaco tip, resulting in rupture and vitreous prolapse.