Snape should have kicked James/Sirius' behinds!!.

[zgirnius]

No: HPFGUIDX 156198

eggplant:
> I don't recall that Sirius (or Lupin or Peter) did ANYTHING to Snape
> on that occasion, just James; and it was not a close contest, James
> mopped the floor with him. At the very least you must admit that James
> never showed the smallest tiniest most microscopic bit of fear toward
> Snape, he just treated him as a joke.

zgirnius:
Wynnleaf, it was not James that cast the Impedimenta. I'm responding to 
Eggplant, as he raised the question.

OotP, Snape's Worst Memory"

> Snape's wand flew twelve feet in the air and fell with a little 
> thud in the grass behind him. Sirius let out a bark of laughter.
>    Impedimenta!" he said, pointing his wand at Snape, who was 
> knocked off his feet, halfway through a dive towards his own fallen 
> wand.