Its not something to laugh about honestly.... Here is an example: https://bitcointalk.org/index.php?topic=2947570.msg30278752#msg30278752
Interesting, had not realized this was possible. Is the concern that if the hologram has any marks (like the black line) the slab could have been opened and the coin swapped out?
No. "Cracking" a coin out of a slab leaves a lot of damage that would be hard to hide. Most of the green label ANACS slabs have crappy holograms. It was an issue of contention with ANACS that caused many to make the switch to ICG for grading.