The electrician needed to run wires to an island in the middle of the kitchen. Instead of drilling down through the stud and running his conduit under the off grade floor; he "wisely" cut a beautiful trough through the old hardwood floor and apparently also the dimensional lumber under the hardwood. As a tile setter I'd be livid and backcharging to reengineer the floor under the house. But is a 1" wide trough cut into a floor where hardwood is going an issue?
Wood is prefinished Australian cypress, 3/4" by 3" wide installed perpindicular to the original hardwood floor. Trench in floor will be around 15 degrees off center of parellel with the new floor. My 290 lb self didn't fall through the hole but strong deflection and bounciness was noted.

Any deflection is a problem. Better have a qualified framing contractor take a look at the damage.

Qualified framer?
I live in Florida. I'm not sure those exist here.
Spoke to the owner and she said her wood guy saw the damage and stated the same that it needs to be fixed.
This was all caused by an electrician that didn't want to crawl under a house to run a wire. Now he has to spend way more time under there fixing his work.