I think the problem is that the jib is to tight compared to the main. When this happens the boat wants to turn down wind.

The advice of unhooking the jib clew may be too extreme though. You can probably get away with letting the jib traveler out and keeping the main traveler tight.

In the past when the boat wants to take off after being righted, I have worked my way to the stern while under the boat (holding on to a rope like the righting line) and then turning the tiller while still in the water.

The trick of standing next to the crossbeam and moving to the top of the boat as it comes up works great. But, I don't see why the crew should be the one that gets to do that...