Often it's very hard to detect which.
But if you're disagreeing on the fundamentals, trying to resolve the disagreement at the details will never work, you need to pop up a layer.
Once you're aligned at the fundamentals, the details resolve an order of magnitude faster.
You were trying to go fast which meant you only had time to talk about the details, but you can't resolve the issue at that layer.
Similar to doing dynamic programming in the opposite order, it's massively more expensive in the end but looks superficially faster in the short term.