I've been meaning to ask the same question. I bought a LandPride 72" RFM this Spring, but mine is a rear discharge. I thought it had something to do with not wanting to clog things up by mowing in the direction of the discharge, but if they have the same warning for side-discharge, I would say its just a safety issue--not being able to see as clearly what you are mowing over. They also said in my book not to make sharp turns, but I don't see how you can effectively use the product to mow around trees and typical obstructions without making sharp turns. The mower certainly seems rugged enough and the wheels turn freely enough to avoid any damage. I presume that its a safety concern to do with having a mower sticking out so far where it can easily swing into a building or tree if you aren't paying attention. Assuming you keep your brain engaged, and do these maneuvers with as much care as you should always exercise while mowing, I don't see what damage you can do to the mower or tractor.