Tax over Dutch government pension in the USA

I have a question for people with Dutch nationality living in the USA and have/receive a Dutch “state pension” from pension fund ABP (Algemeen Burgelijk Pensioen Fonds).
I have served in the Royal Netherlands Army for 39 years, I have a military pension (UGM-Uitkering Gewezen Militairen (Allowance Former Military Personnel)).

Before I emigrated to the USA (Virginia) in Protected content contacted the Dutch IRS International Section (Belastingdienst Buitenland) and they told me that pursuant the USA-Netherlands Tax Treaty, article Protected content . a) I had to pay (income)tax in The Netherlands only, ergo not in the USA.
B.T.W. I have no choice, I receive a net pension, income tax has already been subtracted.

Excerpt from tax treaty USA- The Netherlands

ARTICLE 20
Government Service
Protected content . a) Remuneration, other than a pension, paid by one of the States or a political
subdivision or a local authority thereof to an individual in respect of services rendered to that
State or subdivision or authority shall be taxable only in that State.
b) However, such remuneration shall be taxable only in the other State if the services
are rendered in that State and the individual is a resident of that State who:
i) is a national of that State; or
ii) did not become a resident of that State solely for the purpose of rendering the
services.
Protected content . a) Any pension paid by, or out of funds created by, one of the States or a political
subdivision or a local authority thereof to an individual in respect of services rendered to that
State or subdivision or authority shall be taxable only in that State.
b) However, such pension shall be taxable only in the other State if the individual is a
resident of, and a national of, that State.

When I arrived in the USA I went to the Tax Assistant Center (from the IRS) in Roanoke VA to find out how to file or report my Dutch military pension but they could not help me, they did not have that special knowledge.

In Protected content went to HR Block, explained my situation and showed them an excerpt of the USA-Netherlands Tax Treaty. The local branch could not answer me immediately and send my case to the HR Block Tax Institute. The final answer was that I did not have to report my Dutch military pension and because I had no other income I did not have to file (income)taxes in the USA.
I felt happy because this confirmed what the Dutch IRS (Belastingdienst) had told me.

In Protected content met a guy and while we were talking I found out he was a CPA who worked for a tax-business with an international section. I asked for a double check. This company said I had to file taxes and would get tax credits for the income tax paid in The Netherlands. I did not want to look like a tax evader and filed returns for Protected content 2014. Result was paying back taxes and penalties.

I am still a Green Card Holder and no National (just because of the double income tax)
I still think that I only have to pay (income)tax over my Dutch military pension in the Netherlands and not in the USA, like it is written in the above mentioned tax-treaty.
Is there anybody who can shed some light on this matter?