Resetting track due to defective steering gear?

I recently hit a curb with about 40km/h, which resulted in broken rim and shaky slanted steering. I then let a mechanic’s acquaintance see through it – a track rod was bent, and the half-axle cuff was broken (although probably not due to the accident). Both were changed, and the track was re-set. When I picked up the car he also drove straight ahead. However, shortly afterwards I drove in the car. n vacation – from Vienna to Croatia – and during the ride the car began to move more and more tending to the left. Until I had driven the 600 km to Croatia, the whole thing was so bad that I could not leave out the steering wheel on the highway at all, but had to constantly steer strongly against it (right strenuous…). With a skilful steering wheel I was able to drive a large roundabout, so strongly pulled the steering to the left! he was looking, he re-set the track, could or didn’t want to tell me if the former mechanic had screwed up or not. However, he also changed the steering gear, because it was defective, and put up new (used) front tyres, because the old (though also by steering back) were over. The question is now: Has the first mechanic done something wrong or overlooked something, or can it be that the track is in such a short time only because of the defective steering gear?