The handle is similar in construction and size to what you'd find on a pigsticker. The tang definitely doesn't go through the handle, it's in the handle and goes through a little more than half way. It's tapered to a point so there isn't a big void. 

I guess if you used a chisel like this daily, once every several decades, you might do something to break the handle and have to replace it, like happens with pigstickers once in a while - though many of those still have their original handles. I'm not aware of a good chisel that has the tang going through the end of the handle, though it might be a good thing to combine with softer steel for a work site where someone could be prying with a chisel and hitting it with a framing hammer. 

Two of these are in daily use for the last year or so, and I guess about 30 of my chisels are in daily use with professional woodworkers, I've made somewhere around 200 now and definitely not all of the early ones were perfect - but 100 or so of the remainder are in use with hobby woodworkers. At this point, the two W2 versions of these are a match for vintage chisels of any type - especially the larger ones. The one made from 80crv2 is probably about as good as something from pfeil - the steel seems eerily similar even though they prefer not to disclose what they use.