Anthony should avoid the use of the word "guys" when referring to business professionals. While some people claim that it is gender-neutral, the fact remains that it is essentially a term used for men (as seen in phrases like "guys and girls"). His greeting ("Hi guys") and his reference to the "guys at the picnic" reinforce the idea that he is only considering the male business professionals in his environment. Instead of "guys", he should write, "Hi, everyone", and "everyone at the picnic ..."
He also uses the phrase, "the managers and their wives". This phrase shows that Anthony is only considering the male managers who were present. There may have been some female managers, with or without husbands, but they are glossed over because of the way he uses language. Anthony would have been better to say something like, "The managers and their families", which is completely gender-neutral.
Finally, Anthony said "any man who wants to advance in his career should be serious consider brushing up on his etiquette." This sentence is clearly non-inclusive, as it should really refer to people in general. Instead, he should have written, "anyone who wants to advance professionally should consider brushing up on etiquette.” This