A downed unicycle in front of a crowd.
A man has fallen off a unicycle.
A downed unicycle doesn't necessarily imply a rider who has fallen off.
exists s1 x1 x2 x3.(a_topic(x1) & in(x1,x2) & of(x2,x3) & n_crowd(x3) & n_front(x2) & n_unicycle(x1) & a_downed(s1) & Theme(s1,x1))
exists e1 x1 x2.(off(e1,x2) & n_unicycle(x2) & Actor(e1,x1) & v_fall(e1) & n_man(x1))