Does poking steaks and other meats cause flavor loss? I was barbecuing, during which I was testing my steak for give using the tips of my thongs. But I didn't pierce the meat or jab too hard. A friend said that I'm ruining the steak and that it causes flavor and juice losses. Is this the case?

I've read on the Food Lab that testing meat this way doesn't cause juice loss. But it didn't mention flavor loss. I asked my friend how it alters the flavor and he mentioned that it shifts the juice in the steak, causes it to bruise, and gives it a "dead taste." I looked on here and didn't see a question that addresses this. Also, I looked online and mostly it was about moisture loss in the meat. My instinct is there is nothing wrong by prodding the meat.  I mean butchers smash cube steak with tenderizers. But just in case, am I altering the flavor of my steaks?
This is totally fine. Meat gets poked and prodded all the time, whether to test it, to pick it up with tongs, or sticking a fork in it to cut. Meat just is not that fragile.

Things like smashing with a tenderizer are much more violent and do affect the texture (that's kind of the point), so that's not a great comparison. But this is a really minor thing.