Aircraft accident investigation is a whole procces involving a team of specialists.
The ones that do CVR $ FDAR reading are sitting in a lab, the analyst of the reading do their jobs in offices. If they are able to bring home the remains, the structuctural analysts make arrive to it's part of true in a lab (AF447)
Conclusion is made by professionals who collect all the information and make analysys, must probably w/o traveling to crash site.
Rgds