Cooling off period: 245HB(g)(i) - evidence of absence

[DenSMX]

I have left UK in Feburaury 2013.
I was working under Tier 2 ICT visa.
The ICT visa ends at August 2013.

At Immigration Rules Part 6A 245HB they have specified:

" (g) The applicant must not have had entry clearance or leave to remain as a Tier 2 Migrant at any time during the 12 months immediately before the date of the application, unless the applicant:

(i) was not in the UK with leave as a Tier 2 Migrant during this period, and provides evidence to show this, or ... "

Could you advice me please which kind of evidence will be acceptable here?
Should I provide a boarding pass?
Will the stamp of crossing of my home country border in my passport be enough?

They have sent me a notification of leave to remain curtailment to May 2013.
Can this document be recognized as evidence for 245HB(g)(i) ?