I had this happened to me before, and I don't think this is legal.
My foe summons a high ATK monster
I activate BTH in response.
They chain Torrential to send it to then graveyard instead of RFP.
Now, if you CAN chain Torrential to BTH then it does make sense that everything hits the grave and nothing goes to RFP, but Torrential pretty much "missed" his timing cause it can only be activated to a response of a summon, not BTH activation.
My foe summons a high ATK monster
I activate BTH in response.
They chain Torrential to send it to then graveyard instead of RFP.
Now, if you CAN chain Torrential to BTH then it does make sense that everything hits the grave and nothing goes to RFP, but Torrential pretty much "missed" his timing cause it can only be activated to a response of a summon, not BTH activation.