Some of you are missing the point

Op is not referring to planned hits ie Massino planned the murders in advance and duped them
by claiming he wanted to meet

Same goes for Sonny Black, there was NO sit down. He went and hoped things could be worked out but obviously knew things could go south which they did

Whereas OP is referring to a legit sit down
between two parties that didn’t fare well.

In 9 out of 10 cases they always resolve things at lease on the surface ie Gaspipe had to accept he could not whack Angie. So on the surface he accepted the decision but secretly he started whacking guys

U could say Chin meeting with Gotti didn’t end well since Chin lied to Gotti and most likely pretended to
make peace