I think everyone needs to do what works for them. Everyone has different standards based on the way they decided to live their life.
The issue I have is that they initially said yes, and since checking out the other family is a priority to them, then they did not do a good job—that probably raises a whole slew of other issues.
If a person wants to be a certain way, and has given it genuine thought, and has da’as Torah backing them up, then be that way–but be consistant, and do it with yashrus.