So by ''game physics" your talking only about "game rules".
Like what if the DM gets the ''tense game moment" by simply having Boccob NOT seeing or hearing the spell’s verbal or somatic components?
Ok....but all your examples are only 100% true in our reality. Once you enter the realm of fiction: anything goes.
So are you altering your defination of railroading to ''if the DM wants anything: it's railroading". It sounds a bit like you are.
I guess your ideal DM would be a passive done servant that just did whatever the players demanded.
Yea.....but not really.
The players have a fun game. During the game, none of the hostile players notice the DM ''wanting anything" and at no time do they cry ''railroading".
The players are all happy as clams, deluding themselves into thinking they just did collaborative player emergent game(with that DM servant firmly in check).
So...unknown to the players, the DM did railroad them All the Live Long Day.
The players are busy high fiving themselves at how awesome the game THEY...only the players...made up out of thin air, without that dumb DM ''wanting stuff".
So....if the DM just sits back and smiles....and never tells them the truth. Was there really ever any railroading in the game?
Like sure if there was an NSA spy van outside spying on the game...and all the agents were RPG folks...then sure they...might...see the railroading and know it was done. But still the players will never, ever know.
So...if the players never know....then it really does not matter ''if" something was done or not....as the players will never know anyway.