In the 1968 Chess Olympiad Efim Geller picked up two easy points when his opponents played identical blunders in a line of the Kings Indian Defence. At least that was how it was reported in the British Chess Magazines Quotes & Queries from November 1984. And while the reporting was accurate (Geller indeed did win both games), it looks as though it wasn't due to a trap, as much as two opponents misassessing the resulting position. After White's 11th move it looks as though Black wins a pawn by capturing on e4 but after a series of exchanges, the d6 pawn falls to White's queen, leaving a material equal position. Black may lay claim to a positional edge, but as far as I can see that's about it.
Adamski,J - Geller,E [E94]
Lugano ol (Men) Lugano, 1968
1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 0-0 6.Bg5 Nbd7 7.Qd2 e5 8.Nf3 c6 9.0-0 exd4 10.Nxd4 Nc5 11.f3 Nfxe4 (D)
Two rounds after this game was played, Geller reached this position against Holm (Denmark) and after the capture on e4, he simply resigned. 12.Nxe4 Nxe4 13.fxe4 Bxd4+ 14.Qxd4 Qxg5 15.Qxd6 Qe3+ 16.Rf2 Be6 17.Qf4 Qxf4 18.Rxf4 Rad8 19.Bf1 Rd4 20.Rc1 Rfd8 21.Rf2 Rxe4 22.b4 Red4 23.a4 Rd1 24.Rfc2 R8d2 25.a5 Kf8 26.b5 c5 27.Rxd2 Rxc1 28.Kf2 Ke7 0-1