I mean the dolphin story is gruesome. But for this five to get a severe injury he must be very close to the hole, almost touching it.

The suction power is not that great in an underwater scenario.

What made the dolphin so gruesome is that it was an explosive decompression and besides the driver closest to the door no server dismemberment took place, only a very sudden decompression making for a very sudden yet horrid death.

If the diver in this diagram keeps a couple of centimeters away from the opening he is completely fine but if he manages to cover the outlet hole with some of his anatomy, the shit hits the fan.