Using 'churlish' often suggests a strong disapproval of someone's behavior. His churlish response to the kind gesture made everyone uncomfortable.
Pro Tip 2/3
Cultural Perception
In some cultures, direct refusal may be seen as churlish even if polite language is used. Saying no without a reason was considered churlish in her community.
Pro Tip 3/3
Intensity
'Churlish' implies behavior that is not just impolite, but offensively so. Interrupting the speaker was a particularly churlish act.