When I was young, the knight was sometimes lousy and knights took the cake. It happened more than once that I hammered a knight sacrifice into the rows of my opponent during blitz...the effect being greatly diluted by the fact I only hammered the top half, the bottom still standing on the departing square.
Question: I assume "material malfunction" is practically absent in modern tournament chess (or can you tell anecdotes?) and simply stopping the clock and calling the arbiter does it?