From my understanding what looked like a taxiway wasn't and once they realised they may have hit a light they elected to stop and ask for assistance rather than risk exacerbating the damage.
I also understand that the light they hit was not illuminated either.
Hands up anybody who has never become confused at night at an unfamiliar airfield.
Sounds to me like the aircrew made an honest mistake and demonstrated intelligent airmanship by seeking assistance rather than blunder around trying to recover from a confusing situation.
The fact the aircraft was undamaged would indicate that only pride was hurt and the fact that they were the third aircraft in recent times to do the same would indicate that something more than an error of judgement was at work.