Workers Compensation is usually the only remedy for an injured worker. However, if an outside third party caused the injury, then you may have a claim against them as well. If you obtain a recovery against the third party, then you will need to pay the Workers Compensation insurance company back for some of the money they spent on your case. This is fair, because it holds the negligent party responsible for what they have done. The problem with these cases is that the third party insurance companies simply don't want to pay. Insurance companies never want to pay, and if they can think of any reason not to pay they will stall or low-ball the plaintiff. In these cases, they think that since Workers Compensation paid for some of the case, they shouldn't have to pay anything.
The problem for the injured person is that Workers Compensation doesn't pay for everything. It only pays for 66% of a person's lost wages. It will not pay for pain and suffering. It will barely pay for permanent injury as this is capped by statutory maximums. Finally, as stated above, the actual negligent party should not get out of what they have done just because some employer or Workers Compensation carrier paid on the claim. Part of the purpose of our tort system is to hold negligent persons accountable. When this is done, it discourages negligent behavior in the future. Lack of accountability creates increased risk. Additionally, employers pay enough for Workers Compensation insurance. If some other driver or company is responsible for the injuries, the employer and Worker's Comp carrier shouldn't have to pay for their negligence.
Even though all of this makes sense, third party claims are fought hard. In my last case, State Farm and Fireman's Insurance only offered $1,500 on a case with over $100,000 in medical bills and $80,000 in lost wages. Much of this was paid by Workers Compensation, so State Farm and Fireman's Insurance didn't want to pay. Prior to trial, the insurance attorneys were dismissive and rejected the judge's attempts to encourage settlement. During the trial, the insurance attorneys attacked the plaintiff. They told the jury that he was depressed from getting a divorce almost a decade ago. They told the jury that he had "fooled the Workers Compensation carrier, don't be fooled yourself." They questioned doctors about supposed secondary gain or that the plaintiff was trying to get medical treatment to avoid having sex. (Not sure where they were going with that) Despite all of these defense tricks, the jury then rendered a verdict for $300,000. Even now after the verdict, the insurance companies are trying to avoid payment and are threatening various appeals. The moral of this story is that if you have a third party claim, get ready for an ugly and ruthless fight from the insurance companies. You will definitely need a lawyer who has been down this road before. Don't give up, because they will delay payment, be rude during depositions and mediations and do anything to make you quit. Don't quit.