MH370 speculation after flight wreckage washes up on Reunion Island, page-77

You would be correct, it is protocol. The up side is that the French will take a lot of photos, some paint scrapings and possibly a metal sample to keep on file.

These could possibly be useful if Boeing and MAS end up in a bun-fight duck-shoving blame, with MAS saying evidence has been doctored. Independently held evidence could be useful. It's been a long time, no damage being done by a minor delay.