You have just witness a reason why you've got to insured your equipment if you intend to go pro.
the wedding ceremony doesn't stop just bcoz he fell, or he is expected to continue with the assignment.
Put yourself in his shoe...how do you feel, whether injured or not , also another issue.
so, personal insurance for any accident also has to be taken into consideration.
Supposing, he should have injured his back, break a bone or hospitalised...that means lost of income, upon equipment repair, plus the client might put up some nasty request / demand.
Seriously, looking at a professional point of view...this is not funny.