Ozsync is correct. The pitch mode will remain in TOGA until a different pitch mode is selected or ALT ACQ engages based on the MCP setting. The flight director should pitch for ( in this case) flap 15 speed for MAUW and remain in TOGA.
There seems to be an assumption that he was definitely trying to level off, I think he may well have just been trying to fly the nose back to a reasonable attitude and overcooked the trim element. Ie he kept running stab until he actually had about 15 degrees pitch at which point the machine was trimmed for 300kts.