This can depend on several factors besides what the policy actually says such as:
1. By the adjuster assigned to your claim. Many times the interpretation of the circumstances of your water loss and water damage is determined by what the adjuster perceives or 'wants' to perceive. I have seen instances with the same company where one claim was covered (that I knew should not have been) and one that was not covered (that I knew should have been).
2. By what "You" say or volunteer to the adjuster: This is often very important and even critical when initially telling your insurance company what happened. Often the phrase 'a sudden release' of water or similar wording will normally get you covered assuming the investigation of the loss by the adjuster supports this to at least some degree or at least does not disprove it. The Plumber's report is a big factor when determining this.
3. When it comes to Mold: Some companies simply do not cover mold cleanup (or mold remediation). Most, however, do have at least some coverage for this. Although I have not worked or dealt with every insurance company State Farm has one of the better coverages which ranges up to $5000 on mold related cleanup which includes the Mold Clearance Inspection. This figure does not include repairs of the damage as that is set forth in your individual policy which should be up to the value of the property depending on what you have chosen.
Keep in mind that even if your current insurance company does not cover 'mold', so to speak, does not mean it does not cover the needed repairs. One case I dealt with some years ago involved Farmer's Insurance which did not cover any of the mold remediation and such. But they did cover all needed repairs from that damage. So it is important to understand what coverage you have and what you may need.
It is the Insurance Agent's responsibility to advise you on this and give you the appropriate options. If the agent fails to do this and you are 'under insured' the agent is liable for this which is one reason they are required to carry 'Errors and Omissions' insurance.
I was managing repairs for a property where the agent had volunteered to pay for these for the home owner apparently realizing that the he did not advise the owner on the appropriate coverage to purchase and therefore there was not sufficient coverage under the policy to do repairs. By doing this he kept his insurance license in good standing and avoided a potential lawsuit and hit to his E&O insurance. He was very 'proactive'.