My club was going to be doing some testing on this. As far as i know the testing hasnt been done yet but here is a photo i found the other night from when my dad and i were on the 2001 coast to coast when we were fairly new to 4wding, i was about 16 at the time. We were extracting a Swb Mk from a bog with approx 15m streechy rope (lesson learned never used a rope like that again).

As you can see the bracket has bent and hook has straightened as they are supose to. If you look closer you can also see that the bracket has been pulled from the chassis. The top nuts threads have been damaged. If it had been a pintle hook there may have been a rather heavy, quick moving projectile going for the MK.
I am aware we were probly recovering the stuck truck in an unsafe way with the wrong type of rope but theses things can happen. (Also just notced that one of the bolts isnt a rated one either

Im not trying to say dont use this as a recovery point but for you guys using that as a recovery point (expecally with pintle hooks) to be aware of what can happen.