Bobbles Gone Wild

and I watched a game the other day when suddenly the ball should have been a double play ball, but bobbled 2B and went first, is that the bag error, or FC?

Your third response is absolutely dead right.
The first two answers are people who can really choose a fielder is. That is exactly what it sounds like - it was the choice of outfielder to make a game other than the batter. The only possible way it could be classified as a fielder choice and an error would be if the goal of the second had a bad start to the second. Then it could be classified as a fielder choice, and the second goal could be accused of throwing an error allowing the runner to reach second lead base safely.
Your third answer is also correct in that an official scorer can not assume a double play would have been done.
BaseballJohn has not only the most thorough response, it also has the only correct answer.

Definition of choice Fielder (as defined in Section 2 of Major League Rule Book - (link below)
Fielder CHOICE is the act of a fielder who handles a fair and stock,
instead of throwing to first base to the batter-runner, throws to another base in a
try to put a previous rider. The term is also used by scorers (a) to reflect the
advance of the batter-runner who takes one or more additional bases when the fielder who
manages its attempts to put out a strong hit previous rider, (b) to reflect the progress of
a runner (other than by stolen base or error) while a fielder is attempting to put another
runner, and (c) to reflect the advance of a runner made solely because of the defensive
Team indifference (defended fly).

Again, there may be no choice when the fielder is batting discarded. It may not be the choice of a field player if the batter reaches first base safely.

A wild terrain is thrown by the pitcher that does not allow the Receiver to make a game with the effort. A bullet passed is a field that the receiver does not catch or block with a common effort. For any decision is taken, a baserunner is advancing. If no baserunners on base, it is just a step.

Regarding the double play, the markers will not give an error of a field player for not completing a double play. Your example would have been a marked fielders choice. The batter was credited to advance a base runner.

Good questions.

A wild land is charged to the pitcher when his pitch is so high or so low that this includes any pitch that hits the ground in front of the plate or to the extent that home away from marble receiver not stop or control it to common effort to ensure the batter-runner or advance a base runner.
When the receiver allows a runner to advance by the lack of control land that should have been able to control, it is a bullet that passed.

U can never say a team is about to turn a double play, one game may seem a simple game if a runner in double or single rider off the dough. In the U Describe the situation, it is not an error, BAG OR FC The assessment will DOUGH OUT 4-3. A CF is when a runner before the batter is removed and the batter reaches first base safely. I hope this explains everything u

If a ball bounces, it is always a wild pitch. If it does not work and catch it, or got a glove on this or could get a glove on this matter without too much effort (having to jump or dive for the ball) is a ball passed .

A double play can never be supported. Until it has registered there will never be an error marked on such a piece. It is a terrain. Not a CF (CF is used when the batter reaches the base) and it is not considered a sacrifice (bunted ball was not).

wildcat wells.