IMHO, the best way to carry your Bersa is chamber loaded, hammer down, safety off. Its ready to fire. The long trigger pull acts as a safety. The safety/decocking lever is exactly that - a decocking lever. If you use the decocking lever to lower the hammer, it will not fire. HOWEVER, some folks mistakingly try to lower the hammer using the trigger, slowly lower the hammer with thumb, while the safety is off. I have heard of, and seen discharges this way. Extremely dangerous. The best way is to keep your thumb on the hammer, decock using the lever, and slowly lower hammer with thumb.
If it fires using the decocker, thumb or not, then Bersa will replace it.
If it fires using the decocker, thumb or not, then Bersa will replace it.