A newish trailer shouldn't fail but:
- you have a 50gal fresh water tank, so closer to 420lb of water if full.
- With 1150lb cargo capacity, you would be surprised how quick you hit the limit with seemingly very little stuff loaded (any extra equipment installed...that counts towards payload in addition to the 420lb).
But no, it shouldn't have failed even if over GVWR by a bit. I would put it back on the insurance company that the manufacturer are fighting that it's a flaw. Tell them to pay off on the policy and then they can go fight with the manufacturer if they want to claim it's a flaw...you were involved in an on road accident.
I would be very careful about getting the rig weighed if you don't have to...if everyone is in a pissing match and it shows up over the GVWR, both insurance and manufacture could point to that say it was all your fault.