an agent? Many of these people cannot do it by themselves because they don't have the expertise or understanding. That is why they hired an agent. I don't agree with your analysis.
I have seen real estate agents lie to their clients. I have been lied to by many agents. A client can only make a decision based on the advice and information given to them. If the agent (who has a fiduciary obligation to the individual) lies, you can't put that on the person who is seeking advice.
I have seem agents lie about material breaches of contracts, about offer/acceptance basics, about rights and responsibilities under the contract, lie about the status of development/infrastruture, about the FMV, and about what is "par for the course" on many things. These lies weren't about judgment calls. They were about making things easier for the agent. This is dishonest, and it happens very frequently.
I was a real estate agent. There are some great agents. There are some dishonest ones too. There are many that are just interested in getting the deal done so they can collect their fee.