Hello
It is your decision.
One must respect the work of other people, even if it is deleting elements.
You should have done this:
1 - Check what type of elements were deleted
2 - Check the author, both creator and eraser
3- Contact eraser, asks why he has done that. 
4 Inform eraser that you are going to revert his edition and wait a couple days
5 After a couple of days, you revert the edition 
6 - Only if the eraser repeats what you consider to be vandalism, you can report it to DWG.
Meanwhile it is advisable to discuss it here in order to see what had happen.
As far as I had investigated, Santiago Leitão erased Rudysicion data (totally legal, as explained above) and his own data (also legal).
Best regards
TL
