There are very clear rules for an incomplete tournament but nobody seems to care what the actual rules are for confirming a winner. I can't find coin flip as an option. Maybe there is another rule in the book that says coin flip but I don't see it here. From page 43 and 44 of the ASA rule book:
Incomplete Tournament.
In the event a national qualifier, regional,territorial qualifier or national championship final tournament cannot becompleted within the scheduled time frame the following procedures shall beused to break ties among teams in the same spot in the bracket.
a. Head to head competition.
b. The team that advanced the farthest in the winner’s bracket.
c. Won-loss records, except among undefeated teams.
d. If only two teams are tied for a position and have played each other,the winner of that game.
EXCEPTION: If there are only two teams remaining and each teamhas one loss, the championship must be played or the teams shall bedeclared co-champions. In the case of the ASA Eastern / Northern /Southern / Western National Championship Finals, Co-Champions willnot be declared.
If this occurs, the tiebreaker in Article 310 ( I )( 02 ) ( e, f and g ) of this Code followed in order will be used todetermine the team advancing to the USA National ChampionshipSeries.
e. The teams shall be ranked according to the fewest runs allowed pergame played.
f. If a tie still exists, the teams shall be ranked according to the most runsscored per game played.
g. If a tie still exits, by a coin toss.
NOTE: Only bracket play games should be used in determining theofficial order of finish for National Championship Finals, pool playgames should not be used.