Awww....... colin, don't sweat it. Ya identified it so someone else can do it the right way, next time. Your efforts aren't for naught.
The real thing is, his job is finished and the customer is happy and he gets paid.
If I told ya how many times we talked a customer into something other than what they already have...... Can't count that high.
Funny thing is, I'm working on a directory system for someone this very minute, where they came to us about 2 years ago and asked us to make all kindsa changes, since their old sign shop went outta business cause of covid, I think...... We talked them into our taking all the directories down in the entire building and re-doing them so we had the proper font in our system, since we couldn't match it wortha sh!t. They liked it so much, they had us change 3 other locations. Anyway, they had 2 tenants change and they asked if we could do this and without batting an eyelash, we could. They already forgot we changed the whole system out and are completely happy with the new setup.
In my opinion, type faces, colors, kerning and little stupid technicalities don't matter for this kinda crap. They're directories, advertisements and are meant to navigate or inform people around a maze..... and at a glance. No one is gonna stand there and say, hey, wait a minute, this blue doesn't match what's on their brochure. They're not gonna say, these serifs are slightly different then they were a year ago..... if they even know what a serif is. Signs are meant to be read and educate/inform people. Aesthetics is just a way for different sign shops to 'up' the prices.
In the case of the OP here, looking at the picture, it doesn't look like a critical thing to match exactly and he did just that. It's a holiday advertisement.