Continuity mistake: When the priest is telling Billy to put down the gun, the camera angle from the back shows his left hand making the motion to put the gun down. The camera angle changes to the front and his right hand is now making the motion. (00:11:20)
Continuity mistake: The pre-cut piece of glass that Leeloo breaks through when she escapes is a different shape after it is broken.
Continuity mistake: When the technicians are changing the radioactive fuel of the shuttle, they find shaking bugs and start to burn them. The bugs aren't shaking in one shot. (01:17:10)
Continuity mistake: During the missile barrage on the dark planet, one of the soldiers says, "The planet has increased in diameter by 200%." That means that the diameter would be triple the original size, but it's obvious from the missile impact animations that it hasn't grown anywhere near that much. (00:16:30)
Continuity mistake: As Korben and Ruby ascend the stairs to the opera house, during the chase shot we can see all of their backs, but both before and after there are people behind them that would make this impossible. (01:26:20)
Continuity mistake: When David is waiting for the priest and Leeloo before attempting to board the shuttle to Phloston Paradise, he is chewing on the nail of his index finger. The shot changes to show a different angle of him and he is now chewing on his thumbnail with no time for him to have changed position.
Continuity mistake: When Billy trips on his equipment bag, he fires the gun in an arc that goes up and slightly left. The sparks on the alien go from the center up and to the right.
Continuity mistake: As Leeloo gets off the ship at Fhloston Paradise, in one shot she is looking slightly to her left and in the next shot from behind she is looking to the right. (01:22:40)
Continuity mistake: The shadow of the dark planet is heading in the direction of the sun, instead of away from it, in the scene where the dark planet is approaching the temple. (01:54:55)
Continuity mistake: When Dallas hangs the coffee pot to brew, it's hung at an angle of about 20°. A few seconds later, it's righted itself to a level position and the handle changes to silver lined.
Continuity mistake: When Zorg is showing the the guns to the Mangalores, he is seen shooting the Police dummy, and when he turns to show them that every shot fired afterwards goes to the same place, he is seen starting to fire from his right to the left, but when the camera angle changes he is seen starting from the right again. (00:49:35)
Continuity mistake: When Leeloo is drying her shirt after being in the autowash, she is seen starting to put on the shirt and when the camera angle changes the shirt is on.
Continuity mistake: When Zorg is giving the weapons to the Mangalores in exchange for the stones there is a jump-cut. The jump cut occurs exactly in the middle of when Zorg opens the case then closes it. If you watch it closely you will notice the objects shift position. (00:50:15)
Continuity mistake: When Korben is activating the Fire stone, shots on his face show the match level, but shots on the other three show the match angled toward the stone. (01:57:05)
Continuity mistake: When the Diva is shot and she begins to fall, her arms are outstretched with her palms facing up. The shot changes to behind her and she continues her fall, her palms now face down.
Continuity mistake: After the battle when Ruby is being treated we can see Korben and Vito standing together in the background in front of the security monitors talking and Vito is no longer handcuffed. Then as Ruby screams it cuts away to Korben, and we are seeing Korben standing alone near the monitors with Vito still in the process of getting his handcuffs removed and only then does he approach Korben at the monitors. (01:43:57 - 01:44:26)
Continuity mistake: When Corben bails on the 5-0 (in his taxi with Leeloo), he yanks the police car's winch right out of the car (which resulted in dragging the winch, as well as the entire length of the cable behind his taxi). In the next shot showing his car (4 police cars chasing him down the "street"), the cable and winch have disappeared. (00:36:00)
Continuity mistake: Leeloo's face is dirty outside the building, but in the priest's apartment she's scrubbed clean.
Answer: I looked it up and it is Jill Milan. If you do a search for her, it is in her credits as an actress.