Wow, I am 100% in agreement. I'm an American living in Mexico and find it much harder to be in confrontational situations in Spanish.
My Spanish is good, but I've had almost the exact same "workman" situation happen to me. I'm positive that a native speaker would have picked up on the subtleties of the conversation and not made the same mistake, but pressure like that does not lend itself well to thinking things through carefully while trying to navigate the landscape of a non-native language.
On top of that, I'm highly sensitive to the "Americans are loud and uncultured idiots" image that seems to persist in lots of places, so I tend to err on the side of being polite to counteract that, even to my occasional disadvantage.
My Spanish is good, but I've had almost the exact same "workman" situation happen to me. I'm positive that a native speaker would have picked up on the subtleties of the conversation and not made the same mistake, but pressure like that does not lend itself well to thinking things through carefully while trying to navigate the landscape of a non-native language.
On top of that, I'm highly sensitive to the "Americans are loud and uncultured idiots" image that seems to persist in lots of places, so I tend to err on the side of being polite to counteract that, even to my occasional disadvantage.