"hi guys what can I get you"
That sort of question might go down okay in some places but certainly not in all.
Since we don’t know where Col and his lunch partner were, how can we say what would be appropriate?
At the low end of the market we would probably not even get table service.
At the top end of the market, once seated, the waiter should not approach the table until gestured to do so. An exception could be to refresh glasses but the waiter should ask if the sir or madam requires the refresh before doing so. Another exception could be the delivery of the next course to the table. But then again, the next course should be delivered upon a request from the table not when the waiter thinks it appropriate.
The very seating of madam should be done by sir, not the waiter. The waiter should seat sir not madam. Madam is first and foremost a guest of sir not the waiter or the establishment. If the waiter seats madam then the waiter is depriving sir of the honour to seat madam.
Okay, it may be seen as sexist but that would be the etiquette in a top end commercial establishment where madam is a guest of sir. It is sexist to the point that it would probably not happen if sir was a guest of madam.
At the top end of non-commercial establishments, protocol would take precedence over etiquette and sir and madam should be conversant with the protocol specifically related to the occasion. (Bit of trivia here but Shirley Temple (yes that Shirley Temple but later known as Shirley Temple Black) was the first female chief of protocol for the USA.
An example of protocol taking precedence over etiquette would be the President of the USA not seating the Queen of England at a public function even if the Queen was a guest of the President. It may be done but it would appear as inappropriate.
But all of that is a long way from Penny at the “Cheese Factory”; "hi guys what can I get you"
Chris.