Pretty amazing there are still people arguing that this move was not unsportmanlike conduct. Here's the WPA rule:
"6.16 Unsportsmanlike Conduct
The normal penalty for unsportsmanlike conduct is the same as for a serious foul, but the referee may impose a penalty depending on his judgment of the conduct. Among other penalties possible are a warning; a standard-foul penalty, which will count as part of a three-foul sequence if applicable; a serious-foul penalty; loss of a rack, set or match; ejection from the competition possibly with forfeiture of all prizes, trophies and standings points.
Unsportsmanlike conduct is any intentional behavior that brings disrepute to the sport or which disrupts or changes the game to the extent that it cannot be played fairly. It includes
(a) distracting the opponent;
(b) changing the position of the balls in play other than by a shot;
(c) playing a shot by intentionally miscuing;
(d) continuing to play after a foul has been called or play has been suspended;
(e) practicing during a match;
(f) marking the table;
(g) delay of the game; and
(h) using equipment inappropriately."
This list is not exhaustive and is intended only to provide guidance as to what "Unsportmanlke Conduct" looks like, and clearly, I mean CLEARLY what this player did fits into these guidelines. Loss of game or ejection is really the only question (loss of rack IMO), unless of course the tournament had a separate set of rules.
Pool has to the funniest sport in that there are large groups of players that don't want to play by any real set of rules, just made-up, undocumented, and illogical ones.