What if other teachers behaved like Snape?

[Ava]

No: HPFGUIDX 101279

Cristelle: 
> > If Snape tried something really horrible, why Sirius didn't 
> > tell? 
 
Alla:
> Sirius was not exactly in the right state of mind to go 
> into deep discussions about Snape.


Ava:

Hmm.  I repeat the quote previously cited by Cristelle:

Black made a derisive noise.
"It served him right", he sneered. "Sneaking around, trying to find 
out what we were up to...hoping he could get us expelled..."

I guess Sirius was in the right state of mind to act like he's still 
15, though.