People asking you to take their picture is the kind of thing photographers often have to learn to handle. You'd need to let them know you're shooting video and direct them to the photographer. Doing sports/events I used to get asked all kinds of questions, sometimes I'd feel like what am I, the information booth?? I'd be cordial/friendly and direct them to Will Call, etc. I wouldn't have gone into a concession stand and started selling hot dogs any more than you'd go over to the caterer's table and start serving food. So do you see how stepping in taking photos was doing the photographer's job? When I was taking photos for marketing purposes it would have been overstepping bounds to go to a practice and start lining up players for portraits for player trading cards - because that was someone else's job. I don't understand there being an expection of shooting a photo to deliver as a bonus. It would need to be in the contract to shoot video and photos, even if taking photos was for your portfolio, your business marketing purposes. Using photos of clients for promotional, marketing, business use, etc. without it being in a contract and/or getting releases signed seems to leave you open to potential complaints from clients.