Why didn't the Grail Protectors kill Marcus in the library? They were going to kill Indy and Elsa for looking for the Grail. And Marcus was looking for the Grail too.
shareIt's a plot hole just like several other things in this piece of sh!t movie.
"I really wish Gia and Claire had became Tanner" - Honeybeefine
In Raiders Of The Lost Ark, why didn't the Nazi's, including Toht, shoot at Indy when he was on the front of the truck, or at the tires afterwards so he couldn't drive off with the Ark?
In Temple Of Doom, why don't the thuggees use adults instead of or as well as kids as slaves?
Not being funny but basically the Indy movies are like Bond movies. If you actually think about them they don't make much sense. Which is fine by me because they're deliberately tongue in cheek and an homage to ridiculous adventure serials.
That said, as much as I love Last Crusade, the whole library sequence is all kinds of "What the hell?".
Marcus can't hear the protectors come down those stairs in that quiet place. They made so much noise they might as well have been singing. Then Indy discovers petroleum and lights a torch? Then nothing happens but it does when a match hits it? Then he says he's found a way out but we never see the escape.
It's not a very well done sequence really.
Why kill him in public sight when it's much safer to simply knock him out? It's not even as if he knew who hit him.
Plus, these people were staunch Christians. For them murder would be a sin, UNLESS, it was vitally necessary in protecting the grail.
Marcus posed no immediate threat to the grail's integrity, and perhaps the Grail Protectors had been spying on Indy, Elsa and Marcus and had figured that the hapless and inept Marcus was just along for the ride.