No, from the description, they clearly ignored reports that they "may have hit something", they said "nah, we good." It'll be interesting to see, when the passenger reports start coming in, whether it's plausible the pilots just didn't feel it.
The rules are based on the fact that landing is harder on the airframe than taking off, so as long as max takeoff weight is only a fraction higher than max landing weight you get a pass.
And at any rate you get the greater of 10 minutes or 1% of max takeoff weight per minute to dump enough fuel to land safely. I wonder how long it takes a 737 to circle the runway before it's safe?
20 percent of fuel is used from take off to cruise altitude. On a plane like a 777, that still leaves a very substantial amount of fuel onboard. However on a smaller plane like a 737, you don't have to circle for too long before you're below MLW.