I really think that's what happened to me back in July of 2019. However I have no memory of the event and no witnesses. Just a fleeting memory of a yearling bounding off into the woods and at the time a helmet cracked in 11 places and my skull cracked in 3 places. I really do feel that momma deer must have come out of the brush and jumped over me with her 250 pounds or so.
Glad your friend is apparently okay. Took me till December to start feeling normal again after my concussion. The following anniversary of my wreck I rode the same route and there were five deer standing on the trail where I crashed. Altogether there were about a dozen deer at various places along the 11 mile MUP.
So now when I see that cute fawn or yearling on the road or trail, I'm watching for momma deer and others. I slow down too!