Horrifying case. I don't remember any case, even in times when the mafia dominated gambling in the USA, in which 100 were killed at once.
Perfect example of what underground gambling could lead to. I think that I am not wrong if I say that cockfighting is illegal in Philippines. So a person who decides to cheat in illegal gambling isnt smart.
Regardless of whether it is legal or not there, it is clear that they were betting underground. What I think is whether these people were cheating because they thought they were smarter than the mobster or if they were poor people who did not have many options to have economic resources and opted for this path.