Let us not forget that a large dog's throat/neck area is massively surrounded by muscles. I wouldn't be so sure that strangulation is feasible.
However, dogs are usually pretty self-conscious in regard to their balance. My own Fila Brasileiro bitch gets quite frantic whenever she finds herself on unsure ground such as the kitchen tiles and I've seen other dogs do as much.
FWIW, she weights 175 lb and on her hind legs she's a bit taller than me, at 5'9"...