The only way to avoid it is to kill the titan before he lands. Its incredibly hard to do. Two hits From my blade dancer doesnt kill them. Sticky grenade doesnt kill em...just gotta hope to be gettin smashed by some titan that is already almost dead. And even then you have to react fast to kill them before they land Nova bomb can be avoided by jumping away, Blade dancer can be avoided by running away until the timer runs out, golden gun can be avoided by taking cover until timer runs out. There is no way to avoid the titan smash. Its pretty much the #1 thing that ruins kill streaks in the crucible. You can be the best player in the world on a 20+ kill streak only for it to be ruined by an unavoidable death......

You have very little chance of escaping it.