IRA question

I withdrew money from my IRA during the month of July for a new home purchase. My consultant told me that since this purchase was for a first time purchase I would not be penalized. I informed my tax consultant of this and they suggested that I obtain a form from my brokerage firm indicating that the disbursement was for what I indicated. My brokerage firm informed me that the burden of proof would have to rest with me because they do not want to accept liability in the event that I used the funds for another purchase. The only proof that I can produce is the closing statement from my home purchase and I am curious if that will be satisfactory? My tax consultant cannot tell me which is very aggravating which is why I am seeking other resources for information. In-short how can I avoid the penalty?