Legal Question in Construction Law in California

Absolutely yes. I have spent over twenty years in construction law, both representing contractors in private practice and as in-house counsel to owners, including time as Construction Counsel in the General Counsel's Office at San Francisco International Airport. So I have some experience with this issue. A common cause of claims on public works is "unforseen conditions." A common cause for bogus claims is bids that were too low because the contractor didn't exercise due diligence in determining the job site conditions. The job walk is a legitimate and perfectly legal tool to minimize both types of claim. If you think there was something inappropriate or collusive in how the job walk requirement was applied, you must submit a bid and then protest when the bid is rejected for failure to attend the walk (they cannot refuse to receive the bid, only refuse to consider it), since non-bidders have no standing to protest. But if the job walk pre-bid requirement was done fairly and openly, your protest will fail.