In cannizaro reaction, after the heterolytic cleavage of the pi bond due to the attack of the OH^- ion at the carbonyl carbon, the pi bond is reformed and a H- ion leaves. Why is it more probable that the H- ion leaves and not the OH- ion?

I found out the answer. The OH- attacks the electrophillic carbonyl carbon and the pi bond of the carbonyl oxygen is broken and the electron moves to the oxygen. Since the medium is basic in nature, the H from the OH that had attacked the carbonyl carbon is extracted by the solution. Now, it’ll there will be two oxygen atoms attatched to the carbon. Now, the extra electron on the oxygen forms a pi bond with the carbon and thus, the H- leaves( not the OH- because it will no more exist as OH but as O- and, O- is a terrible leaving group). then, the rest of the reaction proceeds....