The company who made the signs is a pretty good sign company, the website is worth checking out. The design company is also pretty good, they are worth checking out too.
I would like to get my mits on the bid documents, the RFQ and the construction documents. I tried looking for the bid docs as they are usually posted online. All I found was an old pdf with bad callouts asking for engineer grade, these signs require retroreflective.
The sign package is way more than directional signs, they also have some large size monument structures and directories. I think the 250k held back from the sign company is only the portion the sign company is being blamed for.
You have to bid as they are designed, if you do not build to the specs for any reason, you have to request changes prior to bidding is done so everyone bids on the same thing. The client technically can not ask for a major specification change either as that can come under scrutiny from competitive companies.
I'm thinking a bad spec got into the bid documents, someone in the middle changed it due to costs, or a sub contractor cheaped out. After reading the clients idea that the designer and sign company knew more is a cop out. On jobs like this I have volumes of emails printed out in folders and also respond to phone calls with a return email summarizing the discussion to make sure it's documented because of crap like this.
All the city signs I have done are screen printed with 3M Translucent inks (yep, on panels that big) or their cut film since the whole panel is required to be reflective, those panels I have seen for this job are a bit too opaque.