santa

That's a bit harsh, I sometimes do knock over a piece or two, most often the K & Q, and the reason is sight-related: I have difficulties with depth perception.

antichrist

I am known for knocking over a piece or two but I stay away from the queens, inspite of Matt's psycholocial profiling of myself

Igor Goldenberg

Zero time forfeit is also too harsh. FIDE doesn't seem to think things through.
In case of piece knocking is doesn't distinguish between accidental and deliberate knocking (or even touching), even though in China they had at least one arbiter per match (four games).

__________________
For private coaching email IgorGoldenberg@bluebottle.com
Computer tells you what to play, a good coach explains why.

The urge to save humanity is almost always a false front for the urge to rule.
H. L. Mencken

Bill Gletsos

There is any such FIDE regulation that explicitly results in a loss for knocking over pieces.

The action to be taken if a player knocks over a piece is covered by by Article 7.3 of the Laws of Chess.

7.3 If a player displaces one or more pieces, he shall re-establish the correct position on his own time. If necessary, either the player or his opponent shall stop the clocks and ask for the arbiter’s assistance. The arbiter may penalise the player who displaced the pieces.

If they did declare it a loss in China it was either a decision by the WMSG tournament arbiters or specified explicitly in the WMSG tournament regulations.

In fact Chessdom reports on an incident at the WMSG here.
There is nothing in the report to suggest he was penalised for knocking it over.
His problem apparently was that he did not have sufficient time to correct it.

Igor Goldenberg

During team blitz at WMSG forfeit for piece knocking was enforced on few occasions.

__________________
For private coaching email IgorGoldenberg@bluebottle.com
Computer tells you what to play, a good coach explains why.

The urge to save humanity is almost always a false front for the urge to rule.
H. L. Mencken