Goldberg cost Hart with that kick but it wasn't enough to end his career. He got a bad concussion but he continued working with that concussion and even had a hardcore match with Funk after that as well. Hart didn't take time to rest and recuperate, he can blame Goldberg all he wants for that injury but I always feel it's an unfair complaint as Hart didn't know his body well enough to rest after a concussion, instead of continuing to do more matches, and ultimately that's what led to him fucking up his career.