After Randy's character dies, Stan's shield disappears for a short period of time, and reappears after he says "You killed my father!" It also switches from his left hand to his right hand.
In many episodes, it has been revealed that Cartman is terrible at math (or any other school subject) but he was surprisingly able to calculate how many boars it would take to rise up in levels and experience points. This could simply be because Cartman was extremely addicted to the game in this episode.
In the boardroom, a GM says the boys have gained 50 levels in 3 weeks, but Cartman told them it would take over 7 weeks to gain just 30 levels. This could either be a spoof or they just played more than they expected they would.
The boys' love of Warcraft is never mentioned again despite their addiction to the game. They could've just drifted from playing the game.
After the episode, in the next episode, the boys are back to their original body sizes instead of being morbidly obese and pimple faced.
At one point during the late, epic battle, Cartman tells the rest to target the scorpions. It is clearly visible, however, that there are no scorpions in the battle when looking at the boys screens.
At a meeting in Blizzard, the executives discuss how he had killed 5.000 characters in-game during the night. They then point out that there are over 7 million active players, and that they might quit all together. In the real game it would only be possible to slay everyone on one server. He might, however, have become so powerful so that his character could cross over to other servers.
When the camera first focuses on them in the Computer Lab, from the back Cartman is heavily obese despite the fact they have yet to become so. This may be the way that Cartman normally look like sitting, though, due to his weight problem.
If you look closer in the episode when they are killing boars, the camera is from Cartman's view, if you look at his action bar, he has rogue abilities, and under his health bar, he has energy.
When the boys are having their final battle with the nerd, Cartman can talk to Stan, and Stan can talk to Randy in the game. However, in the real world, none of the boys are seen wearing their MMORPG headsets.
The boys have a slower speech pattern when they talk outside of the game, most likely due to their obese state and the stress it is to speak, but when they talk to each other on the game, they talk at their normal talking pace.
The low level monsters in elwin forest are not boars but wolves.