If it was the angels that moved the rock, then Mary wouldn't have known that the body was missing until after they appeared, would she?
The rock was moved before they got there
And why does John say Mary ran to tell the disciples when Mark says they said nothing because they were afraid?
Because Mary ran to tell the disciples by herself, the others went into the tomb and the angels appeared to them.
Thats why Mary said someone took the body and nothing about angels appearing and saying he had risen