the candle that blew over on us

[Arnold Zwicky]

a friend (not a linguist and not on this list) writes about
the expression
   "[this case was] the candle that blew over on us..."
in a context she describes as follows:
   a legislator talking about putting stricter regulation on bounty
   hunters, talking about a case of bounty hunters overstepping bounds
   dangerously (shooting first, asking questions of the wrong quarry
   later, in this case). A "last straw / straw that broke the camel's
   back" thought, at least as far as I expected, but I liked what I
   decided I actually heard - it took a moment to register, and I
   trust I have it right - as a "this lit the fuse" or "this set the
   house (or Mrs. Leary's barn?) on fire" sort of way.

is this a fresh creation on the legislator's part, or is the
expression (which was not familiar to my friend or me) at least
somewhat conventionalized?

arnold (zwicky at csli.stanford.edu)