Dough too wet after rising in banneton?

Toast

Hello, have been fairly strictly following Tartine book for a year now, and getting results I think are great.
It is 75% hydration but when ready, dough is fairly firm.

Once the dough is in the floured bannetons, I leave it overnight in fridge and bake next day. 
(They rise a bit in there.)
Usually they come out of the banneton slowly but surely and cleanly.

Last bake, I let them sit on the bench (warmish day) for 4 hours to bake same day.
They rose a lot and spilled over side of banneton.
When I transferred to cooker, about 1/4 of dough tore off and stuck in banneton.
Cooked Loaves were quite flat, about 1/3 usual height.

Any ideas?
I am guessing the bench fermentation was too much? More than usual.
Not enough flour lining bannetons?

Thanks,

Richard.

If you did everything the same for bulk and the only change was the 4 hour final bench proof then definitely it was overproofed.  4 hours at room temperature is much more fermentation than overnight in the fridge.  As the dough over ferments it gets more acidic and the proteolytic enzymes start breaking down the gluten, this causes the dough to start to become much more sticky.

Benny

of rice and all purpose flour to sprinkle into your bannetons or just plain flour? Rice flour is like Teflon for bannetons.