We as an s-corp are protected against being sued personally, they can only go after the business
disclaimer The following is an imperfect opinion based on my conversations with various attorneys. Each states laws are different as are each individual's circumstances.
People that are in the "right", get sued every day, and they also lose. If the corporation operates as a corporation, then yes it will provide a layer of protection, but there are reasons why the layer is referred to in legal circles as a "veil", rather than an iron mask. You can see through it, and if the wind blows the wrong way on the wrong day, it doesn't even matter if you have it.
If proven through subpoenaed documents that the corporation has failed to follow the laws on corporate viability, then the veil gets even thinner. For instance, if there is any hint of comingling of personal and corporate funds then the corporation may be DOA already. Examples are personal purchases, improperly titled assets, and failure to handle wages/benefits for officers in approved ways. These examples of comingling funds are common in failures of corporate viability. A Forensic Accountant (yep, that's a real thing) can easily expose specifics and establish trends that a court might take into consideration.
Another weak area is failure to act as a corporation. This requires meetings. If there's no established track record of annual meetings, approval of company actions, etc. by the corporate entity, then the court might rightfully question whether or not the corporation is a viable entity. If established that it is not acting as a corporate entity then the corporation offers limited, if any, protection. At that moment the president of the corporation might as well be a sole proprietor in the eyes of the law.
Possibly the biggest risk for small companies is the owner’s personal involvement and/or alleged negligence in whatever caused the liability. If an employee burns a house down, the owner is farther from liability. If the owner is a one-man-shop then not only is the company liable, but so is the owner along with his personal assets. I know of one instance when after getting the max from the insurance company, the plaintiff's attorney convinced the court of the owner's personal negligence partly because he knowingly underinsured the company in comparison to the type of homes, and projects he consistantly pursued.
Tax liability, and business liability are two very different animals, and are proven by different tests. As long as the taxes owed on profit are steadily paid, then the IRS may never care if there are board meetings, look into the way a name is written on a bank account, or consider how an officer gets personal benefit from the business. An attorney suing for $5M because a client’s house burned down with family photos and irreplaceable heirloom items will look at that and more. Depending on what they discover, the corporate veil might blow up like Marilyn Monroe’s dress in The Seven Year Itch.
Of course these are all perfect storm type examples, but that perfect storm day is exactly why business owners look for corporate protection of personal assets.