root pull
The two other photos show a substantial root pull from the deck side. You can see this in the first photo too.
It appears:
1) A small amount hinge wood was left on the side needed for strength to hold the tree as stated earlier.
2) Back-cut was reverse from what it should have been to counter the root pull / tree lean. Regardless of technique, the deck side of the back-cut should have been cut first, wedges established, then cut toward the hinge gingerly.
With regard to Open Face technique here:
The height of the face was short by Open Face standards but does not appear to have had any effect.
The hinge size opposite the lean is unacceptable by everyone's standards.
I would suggest a boring back-cut is less desirable here as it requires a perfect feel for the needed hinge. A standard back-cut gives the faller information on what is needed during the wedge - cut - wedge - cut process near the finish.
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Only PPE appears to be Ear Muffs.
No rope or cable visible.