Audio problem: After the RV rolls into the lake, Jamie asks, "What meeting?" then Bob answers, "The Alpine merger," and in the next shot facing Jamie, Bob turns his head as he is still talking, though nothing is heard. (01:16:10)
Continuity mistake: When the Munros first hitch a ride with the Gornickes, after Bob takes off on the bicycle, as Cassie questions Earl the calculator repeatedly disappears, then reappears, and the books, etc change between shots. (01:18:55)
Continuity mistake: In the scene when Bob is on top of the Gornecke's RV, and they stop suddenly, you can see that the gates of the Alpine beverages company are a distance away. However when they walk around the front of the bus in the next shot, it is as though they pulled up right in front of them. (01:19:50)
Continuity mistake: When bike riding Bob chases down the Gornicke bus, in the front shots their shadows jump from their right to left between shots, while driving in a straight line. (01:22:15)
Continuity mistake: When bike riding Bob grabs hold of the Gornicke bus ladder, his hands grip different rungs between multiple shots. (01:22:25)
Continuity mistake: As Bob hangs onto the Gornicke ladder, when the bicycle falls in the first shot it falls to its left; however, in the next shot the bicycle falls to its right. (01:22:25)
Revealing mistake: When Bob is on the bus' roof there are interior shots of the bus and all its right side (viewer's left) sliding metal framed windows are visible and intact. After Travis stops short, in the following exterior shots four of the double sliding windows have been deliberately removed from their tracks, so the camera's view of the kids is unobstructed. (01:23:10)
Revealing mistake: When Bob hangs upside down on the Gornicke windshield, in the shot facing the bus as he begins to fall, we can see the driver's and front passenger's seats and Travis, his wife, and Jamie are all gone. Of course they are back in the following shot. (Only visible on fullscreen DVD.) (01:23:15)
Audio problem: After reaching Alpine via the Gornicke bus, when Bob says, "Some of my behavior on this trip might be misconstrued as an insult," Bob's mouth/jaw does not match most of his words. (01:25:10)
Continuity mistake: When Bob speaks to the entire Alpine company, with the Gornickes watching, all their shadows move 180° to their right from the start of Bob's speech to Todd's flip. (01:26:45)
Visible crew/equipment: After Bob urges Alpine not to merge, when Carl flips Todd there is a huge straight edge shadow where they stand, however, there is absolutely nothing near the seated people that would cause such a shadow - only the crew's equipment. (Even more noticeable on fullscreen DVD.) (01:29:20)
Continuity mistake: When Gary and Larry catch up with Bob, the trees and snow surrounding the two cars differ after the RV destroys the vehicles; also, note the tree tops. (01:31:50)
Visible crew/equipment: After the State Trooper stops the Munros, when Gary and Larry speak to Bob the reflector screen is clearly reflected in Larry's eyeglasses. (01:31:50)
Continuity mistake: In the shot after Robin Williams has been sprayed to wash off the crap from the RV he is bone dry after the spraying is complete. They only show his upper body at this point but the spraying would have been over his entire body.
Continuity mistake: At the very end when the Munroe family gets stopped by the police, they walk directly behind the RV. A moment later when the RV rolls down the hill (and runs over the police car) it is facing toward them. For it to do this it would have to run over them.
Other mistake: In the scene where Bob is trying to get reception on his pocket PC, he is on a rock and the pocket PC beeps, indicating that there is no signal. But when it goes to a closeup of the pocket PC, you can see in the top left hand corner that the signal is full.
Revealing mistake: When Bob is riding the pushbike down the steep hill to get to his family and the Gornickes at the bottom, in some shots you can blatantly tell that a stunt double that looks nothing like Robin Williams is riding the bike. The stuntman is also visible later when Bob is on the roof of the Gornickes' bus.
Continuity mistake: Just forward of the right rear wheelwell, a small dent disappears and reappears throughout the movie.
Audio problem: The Gornickes and Munro family pull out of the gas station in their bus-type vehicle while Bob is coming down the hill on the bike. There is a "ding ding" sound typical of full service gas stations or auto repair places. These require the long black wires to trigger when tires run over them but no wire is visible.
Factual error: There is no way Bob would manage to get the RV as stuck as it was going up the Diablo road. Just as the top of the road had made contact with the undercarriage the RV would have stopped moving.
Answer: In the world of "make believe", they used "movie magic" to zap the RV out of the water and on to dry land - with no mechanical issues resulting from being submerged. In the real world, someone called a tow truck - perhaps AAA - and the RV was pulled out of the water and it suffered water damage and needed some repairs. This movie was presented as being "real life." Bob left on a bicycle to "try to find help." Near the end of the movie, Carl said that the RV "spent two days under water and they had to fish it out." He didn't say who "they" were. A fishing pole would not be strong enough to reel in a large RV, so I think it is safe to conclude that a tow truck was used to pull the RV out of the lake.
KeyZOid
It should be noted that "fish it out" is a common phrase to mean pull or take out, especially after searching. When people use the term, they're never taking about using a fishing pole. But often when people post questions like this, they're asking for an in-film explanation in case they missed (or didn't understand) something. If no in-film explanation was given, a reasonable speculation can be given. You don't need to remind people the movie is a movie. If the in/film explanation is uncharacteristic to real life, then one can point out that in real life it wouldn't happen that way.
Bishop73
It was meant to be ironic.
KeyZOid
There was no irony, but this isn't the forum for irony anyways.
Bishop73
I guess I failed miserably... but wasn't the original question rhetorical?
KeyZOid