It's a slab, not a wall.
The honeycombing is likely just at the form interface and proves that the contractor didn't over wet the mix.
I've never seen anyone bother to vibrate the form boards on a slab.
Chad Fabry, Rochester, NY
StructureSmart Home Inspections, Inc.
New York Home Inspection StructureSmart The Rochester NY Property Inspector
Chad. While your being piled on I will join in.
While you may not see many people vibrate the form boards most good concrete finishers will tap the outside of the forms with a hammer to stop this from occurring.
Here we use the word "Rat Hole" instead of honeycomb. I like it better.
By the way you are probably correct that the contractor did not over wet the mix. If you place concrete wet you probably would not get this.