Sadly, not being able to trust an alcoholic comes with the territory. It is a common saying in AA ... "How can you tell if an alcoholic is lying? ... when their lips are moving." Nearly every alcoholic lies, it is an inherent part of the sickness. Lying becomes necessary to protect their addiction ... which they will do above all else. As long as an alcoholic is active or in an unhealthy stage of recovery, they will be almost impossible to trust.
There was only one time that I began to relax and stopped worrying all the time about my husband's drinking and it was when he finally made a heartfelt change, attended AA meeting frequently and really worked at his sobriety. It took almost a year before he truly returned to the sober man I had married ... and the trust finally returned. I was finally able to stop worrying about his drinking and enjoyed a normal married life and our kids had the responsible, dependable dad they deserved... but in time, he relapsed and the trust was lost once again.
I agree it is a national tragedy that our court systems do not recognize the dangers of giving unsupervised custody to a parent with ongoing addiction problems. It is now a well known fact that alcoholism is highly resistant to change and alcoholics will almost always lie to conceal their consumption. Yet the courts keep putting kids in the custody of parents that will almost certainly abuse alcohol in their presence ... basically court ordered child endangerment. We now know pedophiles cannot be rehabilitated and the courts would never allow them unsupervised visitation....but they willingly allow innocent children to be supervised by someone that is very likely to become impaired by alcohol or drugs, a potentially deadly situation especially when driving is involved or overseeing very young children that need an alert adult watching over them at all times.
Hopefully someday there will be more effective ways of protecting ourselves and our children from effects of alcohol and the deception that allows this deadly addiction to continue to destroy lives.