Continuity mistake: When Indy and Elsa come up through the manhole their hair is sopping wet and messy. As they run to the boat their hair is magically styled and not sopping wet anymore.
Continuity mistake: During the escape from the Nazis the Jones boys pass through a boathouse and Indy sets a small boat loose with the engine running to distract them. When he releases the boat the motor (and boat) is turning to the starboard side (which would turn the boat straight back into the bank), but when the Nazis arrive, the boat is running perfectly straight down the river.
Continuity mistake: The blood on Indy's left ear disappears at the end of the film.
Continuity mistake: When Indy kisses Elsa in her room in Venice, you can see there is nothing on Elsa's left shoulder, but when the camera angle changes in the next shot, Indy now has his hand on her shoulder.
Continuity mistake: When Indy and his father take the car from the old man, you can see that viewed from behind Henry is the driver and Indy is next to him. In the next shot, they have changed positions and Indy is now driving the car.
Continuity mistake: When the brotherhood member aims his gun at Elsa whilst she is driving in the boat, Elsa ducks downwards to avoid the shot, but in the next angle, she is sitting upright.
Continuity mistake: When Indy and Kazim are about to jump off from the chopped boat, the boat swaps from sinking to floating between frames.
Continuity mistake: Indy slams a pole against the big X on the floor and produces a hole. When the angle changes the shape of the hole is completely different.
Continuity mistake: While in the zeppelin, the German officer extends his baton and lowers Dr. Jones's newspaper, wrinkling it. From the opposite angle, the newspaper is still raised and the officer repeats the previous movements, though this time he doesn't wrinkle the newspaper.
Continuity mistake: Hitler walks surrounded by a huge crowd ahead holding Nazi pennants. When Indy bumps into Hitler, half a second later, the pennants on the left have disappeared.
Continuity mistake: Dr. Jones hugs his son and walks 20 meters away. When he turns around to address him, he is barely 5 meters away.
Continuity mistake: When a jeep gets stuck to the tank's cannon, the type of jeep, its position and the damage done changes between the first and second shot (watch how the smashed windows fix themselves, for example).
Continuity mistake: The position of the stone that Indy places to block the cannon changes between shots.
Continuity mistake: In front of the main tribune there's a pile of burning books. First the fire is just atop, a frame later the whole pile is burning.
Continuity mistake: After Indy and Elsa exit the catacombs through a sewer and start to run away, a woman in pink turns her head to watch them leave and then turns around to see Kazim's men run after the couple. A frame later, from a new angle, the woman's head is turned 45° facing downwards.
Continuity mistake: Sallah rescues Dr. Jones from the tank and stops by the cliff. On the next wide angle he's nowhere around.
Continuity mistake: Indy stops his sidecar at a crossroad, meters ahead of a house. When the angle changes he is now several meters behind.
Continuity mistake: During the crashes by the border control the road keeps swapping from sunny to shadowy back and forth in less than 3 seconds.
Continuity mistake: When Indy jumps on Kazim's boat, Elsa's boat is inches away from Kazim's, but a shot later she has managed to appear somewhere else with no boats around.
Chosen answer: They're not, no. An individual doesn't become immortal after one drink - it requires them to drink regularly in order to remain alive. So neither Jones has been rendered immortal, merely healed of any wounds that they might have. But your surmise is basically correct - as the Grail cannot leave the shrine, any individual wishing to use it to prolong their life must stay there if they wish to enjoy its effects.
Tailkinker ★
Also, in Indiana Jones and the Kingdom of Crystal Skull, Henry Jones, Sr has passed away before the start of the story and therefore was not immortal.
raywest ★