DNA deals a Deadly Blow {{{Spoiler}}}} Too tidy a departure?

Whoa, Mama, and Daddy!

So here are three human beings caught up in a friggin' maelstrom of emotional accusation, denial, longing and exploration which puts their past, present and futures on the line...

Then along comes a scientific judgement on the DNA match (or not, in this case) and suddenly it's all "Never mind," ~ time to jettison all they've been through, call a cab and hit the road to the airport, after which they'll be conveniently, or tragically, bi-coastally distanced from any further likely encounters???