True flat-Earthers believe that the Earth is flat and that the widely accepted model of a spherical Earth is a conspiracy or a misunderstanding. In this belief system, they would likely assert that people who claim to have friends or co-workers more than a few hundred miles away are mistaken, lying, or part of the conspiracy.
In your example of a colleague 8000 miles east with a significant time difference, a true flat-Earther might resort to various explanations to justify the inconsistency:
Conspiracy: They might claim that the colleague is part of the conspiracy to perpetuate the false notion of a spherical Earth and is spreading misinformation.
Light Bending: Some flat-Earth models suggest that light bends in certain ways, allowing the sun's rays to reach farther areas even though they should be obscured by the Earth's curvature in a spherical model.
Alternative Explanation: They may come up with alternative theories to explain the time difference, such as local time variations or different sun movements on the flat Earth.
Denial: Some flat-Earthers may simply deny the evidence presented by their colleagues and maintain their belief without logical explanations.
It's essential to understand that true flat-Earthers have a fundamentally different worldview, and their beliefs are not based on empirical evidence or scientific consensus. Engaging in debates with them might not be fruitful, as their position is typically resistant to change, and they may rely on unconventional arguments to defend their beliefs.