Why did this A320 stall protection demo not hold Valpha max? This video is about the Airbus A320 High angle of attack protection

                
             

At 4:54 - 5:13 why did it pitch down? I know it is  trying to maintain Valpha max but if it would have stopped following Valpha max it was at around 200 knots and could have kept climbing at a very good rate. Instead it maintained Valpha max but when it maintained Valpha max the speed decreased and and it pitched down and thus the vertical feet per minute started to decrease. 

I thought it was suppose to maintain the highest possible lift and if it stayed at 200 knots with the pitch up the aircraft was climbing at a very high rate but it pitched down and slowed the aircraft so it wasn't climbing at its max performance.
You need to look earlier in the video. At 3:59 the sidestick goes full back and full left. The aircraft exceeds the 33deg bank limit on automatic maintenance of pitch and bank, requiring the pilot to hold pitch and bank. 



The pilot is in command from 4:54-5:13, not choosing Valpha max. He hits the bank angle and stall limits to demonstrate flight envelope protection, the point of the video.