I captured these two shots from Transformers Dark of the Moon.

The lady was pissed when addressed as "Ma'am". However, Colonel Lennox surely meant no disrespect, as military protocol advises that officers may use "sir" or "ma'am" when addressing anybody.

My question is: In real life, if I don't know her name, real age or occupation, how should I address a lady like her in an elegant way without offending her?