I guess I failed that validation attempt, ya think?
Well we can't be perfect all the time can we

I think it's also how you look at things. Dealing with people with BPD can be quite challenging and most if not all of us aren't born with the knowledge and skills required to do this. This is something we learn as we go along often through a process of trial and error. We can learn from our errors and so in the long run transform them into a catalyst for success.
Validation isn't easy with someone who has high validation needs. With validations it's important to keep in mind to validate the valid (and only the valid):
Let's first look at the importance of being true and authentic to ourselves. If we can't be true and authentic, we are sacrificing ourselves for the benefit of another, and we are most likely enabling another person's dysfunction. This helps no one.
For these reason, validation is never about lying, it is not about being ruled by the emotions of others, and it is not letting people "walk all over us". We never want to validate the “invalid”.
Validating someone's thoughts, feelings, or beliefs does not necessarily mean we agree, overall, with what they are thinking, or feeling, or with their behavior.
Do you feel like there was anything in your husband's behavior and experience that you were able to sincerely validate? Do you feel like you were validating the valid here or possibly something invalid?