There has been a lot of debate about whether the rebar stub out was acceptable but the alternative, a 4 gauge copper pigtail has the habit of being gone before you can get back there with the panel you need to terminate it in and there is no real way for most 1&2 family electricians to splice it. CadWeld molds and the big crimpers for a legal splice are not usually on their truck. As long as the rebar is protected from the weather it seems to work OK.
