That's an example of what can happen if you go into the foamy water of a wake.
The foamy water doesn't support the hull ... starboard hull side drops into the bubbles, and off to starboard you go.
Fun if you are 50m behind.
Not so much fun from almost alongside.
If the manoeuvre was intentional, then it's simply dangerous. If it happened due to law of physics as FlowerPower describes, then why didnt the skipper just back off the throttles, he had plenty of time to react in my opinion.