weatherby PA 08 release trigger?

[edp]

Hi I had found out today while shooting sporting clays that my PA 08 12 gauge will fire with releasing the trigger! When I have just fired a round, pumped the spent and chambered a new round and held back the trigger while doing so, it will fire when I release it, kind of scared me. After I got home cleaned the gun and tried it dry firing it did the same thing again. Any one else have this happen to them? Is this a malfunction or design flaw I wonder, any comments would be appreciated, thanks. I tried finding something on the net but no luck.