A 16k hitch may, MAY, be at the limit for that size trailer, but the bigger issue is that it was used. I really doubt you bought this from a dealer as they will refuse to sell any hitch that's been used in any way - just because of this problem. If you bought it from an owner and they didn't make you sign a release of some kind, they are most likely liable for what happened and your insurance company will turn them into mincemeat. Reese, nor any of the other hitch makers makes junk. Everyone has their own preferences as to brand, but having a failure like that means something was either not installed right or the hitch was broken to begin with.