The purported breach of protocol happened shortly after Flight 1246 landed at Bush Intercontinental Airport here on Monday, and pulled up to a gate, CNN reported.
There were 159 passengers and six crew members on board the flight that came in from Sacramento, California, the network quoted United Airlines (UA) spokesman Charlie Hobart.
He did not identify the flight attendant.
No one was injured during the incident, which recalled another -- much more famous -- time a flight attendant pulled an emergency slide.