Let arrogance walk far enough and it eventually leaves footprints back to the weakness.

Arrogance overreaches by design, because it does not check itself. Given enough room, it will claim more than it can support, and the overclaim is where the actual weakness becomes visible to anyone paying attention. You rarely have to expose it. You mostly have to not interrupt it.

When someone is overstating their position, resist the urge to challenge it immediately. Ask questions instead and let the answers accumulate. The gap between the claim and the substance tends to show itself without your help.