I'm not surprised in the least when people are dismissive of anything they are ignorant of as if saying; were it important I would already know it. Its just like the anti-Catholics who profess to know more than the Magesterium about what Catholics do and don't believe without ever having actually studied it.
How should a Trinitarian Christian respond when some fool or heretic posts "Jesus OR God"?
Generally speaking if you know the persons intent and they are on topic...you just let it go. Easy...especially since the poster is known to also be a "Trinitarian Christian"...as you have named.