That is impossible to answer without review of the order and the proceedings in the case. I can't imagine how a court could order if there is no trial, as you claim. That makes no sense.
Speak with a tax lawyer.
This answer is for informational purposes only and is not legal advice regarding your question and does not establish an attorney-client relationship.
Does a Tax Court decision that is entered pursuant to agreement of the parties have any res judicata effect?
You may contact Attorney Jeff Collins directly at email@example.com, or 866-340-5055, for more specific answers. This forum is merely for open, public discussion. Discussions in this open, online forum are not intended to create an attorney-client relationship. IRS CIRCULAR 230 DISCLOSURE NOTICE: IRS Circular 230 regulates written communications about federal tax matters between tax advisors and their clients. To the extent the preceding correspondence and/or any attachment is a written tax advice communication, it is not a full “covered opinion”. Accordingly, this advice is not intended and cannot be used for the purpose of avoiding penalties that may be imposed by the IRS regarding the transaction or matters discussed herein. Each taxpayer should seek advice from an independent tax advisor with respect to any Federal tax issues, transactions or matters addressed, discussed or referenced herein based upon his, her or its particular circumstances.
Are you asking about a Tax Court decision that was entered based on a stipulation between you and the IRS?
If so then the answer is yes. The order is no less a binding order of the Tax Court merely because it was based on a stipulation between the parties. The same goes for any other court. As such yes, it has res judicata effect.