I assume this is the same defective water slide case:

https://www.casebriefs.com/blog/law/civil-procedure/civil-pr...

Here, the issue was whether the defendant manufacturer could amend their pleading to deny manufacturing the defective water slide after they had initially admitted it. The court found that they could. Subsequently, a special jury found that the defendant did not manufacture the water slide and the judge granted summary judgment for the defendant.

If I recall correctly, it was the installer that had gone out of business or was otherwise unreachable and the water slide was unmarked as to the true manufacturer, which left the plaintiffs (or their insurers) out of luck.