In the first flashback scene of Randy's football game, the scoreboard behind Earl shows the visiting team has 13 points. As the game is ending (Earl is standing up signaling to Randy not to score the touchdown), the scoreboard shows the visiting team only has 10 points.
An electricity needs a two points of contact in order to move. When the impound guys turn on the electrified fence while Earl and Randy are on it, they have one point of contact; therefore, they would not have been electrocuted. Also, assuming it would electrocute them, they would not have been thrown from it as they were grabbing onto the fence (muscles contracted) they would have just involuntarily grabbed harder.
Randy said he bet $3000 on his thrown game, allowing him to use the winnings to retrieve Earl's car. Where did this $3000 stake come from and why did Earl and Randy simply not use this to pay for the release of the car?