That's a well crafted PR response that does it's best to accept responsibility and give a plausible explanation, which is what's expected. Doesn't mean its true.

It doesn't really fit well with what's in the image to my eyes though.

Maybe a second person saw the ticket, thought someone missed a word and added it, but that doesn't make sense at a high end place to have just anybody doing lettering.

Looking at that 'Happy Birthday' on a plate and thinking something needed to be added, I would not want to touch that perfect cursive even if I had similarly impressive flow, I can't imagine the different shape wouldn't be acceptable at a place like that.