This is what root cause analysis would call a "training issue". You're shooting a nice slick, smooth DA trigger, with what? an 8lb pull, 10? 12?, doesn't matter all that much, what matters is that the rated pull weight is the maximum pull on the trigger needed to operate it all the way through.
Your finger gets on the trigger and all too easily applies some pressure, in anticipation of the DA pull. 2-3lbs, maybe, maybe more its easy to do, put pressure on that DA trigger until you feel some resistance, THEN start to actually pull the trigger. Maybe you've got a DA/SA semi where you have some distance to take up before you are actually pulling the trigger...
DO that to a cocked revolver, with a 2-4lb trigger pull, and no take up, or slack in the trigger movement, and bang!! You just fired before you were ready.
Your finger is doing what you trained it to do, you probably don't even realize it.
Firearms operate on two levels, conscious and unconscious. People use lots of terms but they're all the same thing boiled down. IF you have the time, and take the time to think about what you need to do, you can run a lot of different guns well. If you don't, you are going to do one thing, the thing you do most often, and do it without thinking about it. If the gun in your hand at the time is the one you use most then you'll do the right thing(s) and it will be well. If the gun in your hand isn't the one you use most, and your unconscious actions aren't the right things to do, it can be bad...
A long time ago, circumstances put a friend's Browning Sweet 16 in my hands as a pheasant flushed in front of us, rather than my own Winchester Model 12. I had shot the Browning before, it was a fine gun, but not for me, that day. Because the bird was unexpected.
Heading straight away, I had some time, mounted the gun punched the safety OFF, and pulled the trigger.
Nothing. Not even a "click".
In the very brief time before the bird was gone, I did it TWICE more, punched the safety off and pulled the trigger. Exactly the same results as the first time. My reaction was instinctive, and if I had been holding my Winchester, I would have gotten the bird. But the Browning's safety is BEHIND the trigger, where the Winchester's is in front, and that's where my finger went, each time, because I wasn't thinking, I was just doing.