So your problem is a product liability claim. From what you have described there is a good probability you would be found liable for the injuries if you cannot adequately defend the claim with something such as the user is liable because they used the product not as intended or somehow damaged the product leading to the incident
if the user received anything more than some simple basic treatment you can be assured the medical expenses far exceed "in the thousands of dollars".
It it would be a really good idea to consult a local lawyer to review the situation. There are a lot of issues here that can only be dealt with by an attorney who has the ability to review all of the facts.

