In NBA Rule Book, are "vicinity of bench area" and "altercation" defined in the rule.?

Big controversy in the NBA playoff series between Suns and Spurs as to whether or not two Suns players should be suspended for the next game because they "left the immediate bench area during an altercation." Many people have said that the Commissioner had to suspend them as "a rule is a rule" and there is no gray area in this rule. I beg to differ. If "immediate vicinity of bench area" and "altercation" are not clearly defined, then those terms are left up to the interpretation of the league and actually could have given the commissioner an out had he wanted to rule that no suspensions were warranted.