A more thorough explanation:

Vouching-in is a legal term that refers to a procedural device used in a lawsuit. It involves inviting a third party who may be liable for the subject matter of the suit to intervene and defend themselves. This is done so that if the invitation is denied and the defendant later sues the invited party, the latter is bound by any determination of fact common to the two lawsuits.

1. In a product liability lawsuit, a manufacturer may vouch-in a supplier who provided a defective component that caused the injury. By doing so, the manufacturer can shift some of the liability to the supplier.

2. In a construction dispute, a general contractor may vouch-in a subcontractor who performed faulty work that led to damages. The subcontractor can then defend themselves and potentially share in the liability if the court finds them at fault.

These examples illustrate how vouching-in can be used to bring in third parties who may be responsible for the harm or damages in a lawsuit. It allows for a more comprehensive resolution of the matter and ensures that all parties who may be liable are held accountable.