My Indian friend told me when he had house warming party, he invited some Muslim friends and assured them that the food was halal. On that particular night one of them (quite close to the host) went with her family much earlier than indicated and when she reached the house, all she saw was the host family members and some family friends (non-Muslims). Then she had the audacity to ask the host " why no Muslims , food not halal ? then she and her family decided to go back.  She herself went there so much earlier and saw no Muslim and just assumed the food not halal. If she had went there a bit late, she would have saw many Muslims and the Muslim caterer. The host told me no more future invitation for her for any function including those not involving food.