Urgent question pushing film / clip test

I shot Tri-X 220 ISO 320 at ISO 1280. I've left it into a lab to do a clip test coz I'm a bit nervous of it.

They said they'd give it 3 stops initially.

Is this right, I thought upping 320 to 1280 would be 2 stops :confused:

Help please

Call them back and ask THEM. A real lab won't blink at the question.

If I hazarded a guess, it would be they have experience with the film and find that reciprocity comes into play and it requires an extra stop of push to get that ISO.

Just my guess...