Beware of Mountain Bikers at Deam Lake. Yellow Trail around Lake is multi-use 6-mile loop

I was told this story and as best as we can figure out this is how it unfolded. I wish we knew the names of the Louisville men.
On December 1^st, two men from Kentucky were day riding at Deam Lake and after riding out the yellow trail and then turning right on orange they headed towards the red trail at the intersection of Tree Lane and the Donkey “jack” on the corner. After encountering the jack that shook up their horses they proceeded – right on to the red trail heading back to the day parking with ½ of their ride still to go. Out of no-where from behind 3 men on mountain bikes came upon the horse riders and scared their horses into a bucking fit, both were thrown, one with a broken arm or wrist and a head injury. The other man escaped with no visible injuries. The bikers stopped and helped the men. Along came Jerry and Juanita Hobbs, horse riders from New Washington, Indiana also parked in the day area. Jerry knew the area well and rode back to the day parking with the uninjured man to get their trucks and trailers and drive some distance around thru the country to where his buddy was. Juanita stayed with the injured man. When the trailers arrived the horses were loaded and they headed to the hospital in Louisville. The bikers were not on the designated bike trail when this happened. The only bike trail in Clark State Forest/Deam System is the Yellow Lake Loop – 6 miles.