A tug working indirect can have substantial effect on a vessel behind it in stopping or direction.
However the speeds involved in this incident were somewhere between direct and indirect.
Please a tugmaster jump in here.
As I understood it you have to be doing over 10kts for a tug to be effective indirect, hey and it looked awful scary from my point of view, then somewhere between 10 and 6 kts a tug is much better direct.
Please tugmasters jump in here.
My experience with tugs is from driving conventials, to being a pilot with twin voiths or twin ASDs.