I apologize for the cross-post - new to the site...

We had a leak from our hot water line in the concrete slab. That line was subsequently re-routed above and behind the dry wall because the leak could not be located. The leak was noticeable when the engineered hardwood floors became discolored and started buckling in some areas. Luckily the house was still under the builder's warranty. The wood floor has subsequently dried and the water stains have disappeared in some locations, but my concern is now about potential mold issues. Should I be concerned and have the builder rip up the entire floor and replace with new flooring? The builder is obviously not down with this and have indicated that they would only replace certain planks near and around the leak area. Would the new planks even match the current color? What would you recommend? Any advice would be greatly appreciated.

You can count on the replacement panels not matching. Each manufacturing run will have a slight color difference. Unless the contractor can pull replacement panels from the same production run I would count on having to replace up to a room division or some similar to this plan.

JGARNER thanks for your response.
How about mold issues? Should I still have a concern eventhough on the surface everythings seems to be dry? I mean the wood must surely be damaged right?