If the father who sets up a living revocable trust dies, the trust owns an annuity with an adult child as the annuitant. Are there any tax implications? Pay outs?

There could be a bunch. For starters, what does the trust agreement say?

And are you sure the annuity is really owned by the trust?

"Annuitant" is not owner or beneficiary.  Sometimes a younger person is named because older ones don't qualify.  Theoretically, it has been explained to me, someone can be pulled in off the street to serve as annuitant.  

How did the employer get involved?  Is this really a 401(k) ?  Was the deceased an owner of the company and this was some plan like split-dollar insurance that I avoid learning about?

Thank you so much for your response. My apology.  The 1099R (Code 6) was from the Ohio Insurance Company. The funds were paid to the Trust.   In my 36 years of practicing, I have never encountered a situation like this one. I have read the Trust document, but I have not had access to the Annuity Contract. The financial planner sent me an e-mail stating that the annuity contract was owned by the Trust of the purchaser of the contract,(the deceased) not the individual, and the contract was based on the life expectancy of the adult son, the annuitant. The Trust is also the beneficiary of the contract. The financial planner stated that this is the first annuity contract he has encountered in his 20 yrs of practice set up this way.