Oh yes, why I had two free battle matches where I utterly destroyed the opponent's team with Bisharp alone, and both of them have ended with the opponent disconnecting.
First match was Bisharp up against Lapras, Aegislash, and Mega Venusaur, Bisharp brought Mega Venusaur down to critical health with a +2 Iron Head, opponent decides to switch in Aegislash only for Bisharp to OHKO it with Knock off. Following this the opponent sends in Lapras, and Bisharp OHKOs it with Knock off.
The opponent then rage-quits following this, and I facepalmed hard.
Second match was against someone who used a battle spot team composed of Milotic, Charizard Y, and Rayquaza. Bisharp gets a +2 Swords Dance off while Milotic uses scald (not burning Bisharp). Bisharp on the following turn OHKOs it with Knock Off, opponent sends out Charizard Y and Bisharp OHKOs it the following turn with sucker punch. Finally the opponent sends out Rayquaza, one sucker punch from Bisharp and it's dead.
Opponent disconnects the following turn after all three of his pokemon are defeated, and I'm just like: "Really dude, you are a horrible person."
And more recently an opponent disconnects on me during a RATED battle, because I One shotted their Talonflame, volt switched on their Greninja, and burned their Hitmonlee with my Tentacruel's scald.
Good grief, at least show some good sportsmanship and bow out gracefully like honorable battlers do when you know you're cornered. Seriously, disconnecting on your opponent is the worst thing that you can do, because it's not only childish but also shows that you have absolutely no respect towards your opponent.