Obviously, the T34 won't win. But it will delay the whole action enough for an ATG to come in, potentially a snare, in team games a team mate can rush for help and flank your tank. It's very dangerous to just stand there for so long. With only one single P4 and no additional vehicle or ATG, there's a good chance that it is not worth attacking the T34, because a probably outcome is that you get your tank damaged and have to repair, costing you overall more micro and time than the opponent (who just has to wait a bit longer for the ability to finish).
This was my biggest takeaway from the test.
However, I would like to bring the discussion back on topic to ask once more: "isn't this kind of stupid?"
We're over here discussing how the T34 can actually *fill up holes in its armor* fast enough to effectively give the tank KV-1/ Panther levels of health. And this is assuming worst case scenario where all P4 shots penetrate. If RNGesus is not smiling upon you this day, well you had ought to add each missed shot to the number of shots you're gonna need to kill the damn thing.
I personally think that once a tank in crew repairs gets hit, it should either A.) do double damage and instantly cancel the repairs, or B.) do normal damage, but crew stun the vehicle like Target Weak Point does, while at the same time cancelling crew repairs.
This makes way more sense and also as an added benefit doesn't look completely silly.