Do or Does - help please [duplicate]

If you or your attorney do not call me by 5:00 p.m. today, then I will go ahead and file a complaint.

Do v. Does

'Do" sounds best, but why? Which is correct to use: do or does?

Does. Here's reference: Look at this document from Purdue University's writing lab. https://owl.english.purdue.edu/owl/resource/599/01/

Point 3 clearly states that the verb should take the form of the nearest subject. (Attorney) Also, since both are singular joined by 'or' there will be no plural form of the verb. If this were 'and' it would be plural (do).

Do. I agree. Why? Perhaps because a call from your attorney would be understood as in effect coming from you, since the attorney represents your interest, so "you" dominates in the disjunction. We could think of "or your attorney" as being a parenthetical addition.