Originally Posted by
Skatering
Have you checked the I-94 website to see if they've recorded an exit? If so, an exit that wasn't to Canada, Mexico or the Caribbean should be a 'clean' exit.
Even an exit to Canada, Mexico, or the Caribbean can be a 'clean' exit.
If departing by air,
CBP's I-94 automation Fact Sheet advises that "travelers issued a paper Form I-94 should surrender it to the commercial carrier [or] CBP upon departure." In addition, the airline's APIS manifest is matched up with the CBP I-94 issuance data in their systems. (Although for an example of how that go can wrong, see this thread:
Visa Waiver Program - I-94 Expiry - Compliance Notification Email )
If departing by land, the visitor should hand the paper I-94 (if they were issued one because they entered by land) to the CBSA border guard on the way into Canada, or a CBP officer on the way into Mexico.
CBP INFO Center answer:
If you have a paper form I-94 and depart by land, you can turn the form into Canadian Border Services Agency (CBSA) upon entry into Canada or to CBP at the port of entry prior to entering Mexico.
former Inspector's Field Manual (FOIA PDF part 2, page 4):
Signifying departure on Form I-94 with a CBP Admission Stamp:
In the routine course of operations, you will receive departure portions of Form I-94, Form I-94W or Form I-94A. This may occur when individual aliens seek to report their departure, or carriers and border management officials return departure Forms I-94 under a local operating agreement. ...
... In some circumstances, at some locations, border control officials from Canada or Mexico may apply their admission stamp to the reverse of a departure Form I-94. If the date on a Canadian or Mexican admission stamp reflects a current departure from the U.S. and entry to contiguous foreign territory, this is acceptable as evidence of departure from the U.S.
IFM (FOIA PDF part 8, page 10):
(c) Departure I-94 forms and other documents. Collection of departure I-94 forms at land borders has always been difficult, resulting in inaccurate Nonimmigrant Information System records. Canadian immigration officials collect some departure documents for DHS, other I-94 departure forms may be retained by the alien for reentry. Collection boxes for depositing some departure I-94 forms are in place at some Mexican border crossings.
...
Departure forms collected by Canadian immigration or deposited in collection boxes should be reviewed to insure departure information is endorsed on the back and regularly forwarded for data entry ...
IFM (FOIA PDF part 10, page 2):
Document Collection. Canadian officials have agreed to collect departure documents (Forms I-94) for INS when they encounter nonimmigrants entering Canada who will not be returning to the U.S.