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Losing a game over the board is bad enough, but to lose it for other reasons can be especially painful. By now most experienced players are familiar with the dreaded mobile phone forfeit, but if you've played chess long enough, you eventually learn there are other ways to hand over a point.
Oversleeping is always a goody, and looking over Bill Egan's book on the Doeberl Cup, I see that a few players have fallen foul of this. IM Aleks Wohl did this on at least two occasions, missing out on playing GM Eduard Gufeld in 1988, while I was even guilty of this offence in my first Doeberl Cup in 1985 (In my defence I had worked a 10pm to 6am shift, and my mother ignored my instructions to wake me at 9am).
Flipping a chess board is a rarity, but I know of at least one incident (at a local club) where a player upended a table, and walked out before being defaulted. (It seems that the player had tangled his bag around the table leg, and in grabbing the bag, upset the table.)
Of course with the various "no draw before x moves" rules in play, it is now easier to be double forfeited. This has happened on occasion, but not in any tournaments I've directed. On the other hand, failure to report a result has resulted in me recording 0-0 in lots of tournament, usually in blitz, but also in at least one Doeberl Cup.
Fortunately the one object that has caused more forfeits during the game (the mobile phone), is probably responsible for less accidental forfeits by sleeping in. Whether it has been a net gain, I'm not totally sure.