Foreign Border Control Took I-94 when We Forgot to Turn it In

[SuperSixZero]

My foreign born, Israeli girlfriend and I travelled to Boston to visit my family in the winter.

She has a spotless visa entry-exit record and this was the second time she was travelling to the US with me.

Our return flight to Israel was: Boston to Canada, and from Canada to Israel.

The airline never asked, nor did we remember to give her I-94 form up in Boston at any time. We did not realize this until we crossed Canadian border control.

Upon realizing this we surrendered her I-94 form to the Canadian border control, since we thought SOMEONE needed to take it...

-It was an I-94 (white regular) not a green one, nor the visa waiver program.
-We flew AirCanada, a commercial airline.
-We still have all ticket stubs/bordering passes for the both of us.

1) Will turning the US I-94 form into Canadian border control make it problematic for her next US visit this summer?
2) Will we need to provide more proof than just bording passes/tickets, that she left?

Is the website titled: "I forgot to turn in my I-94 when I left the U.S., what should I do?" a good start?

[Mr. Knowitall]

What type of visa are we talking about? If she was simply visiting your family I would have expected this to fall under the Visa Waiver Program. The USCIS article you reference states,

Under the Visa Waiver Program (VWP), visitors who remain beyond their permitted stay in the United States cannot reenter the U.S. in the future without obtaining a visa from a U.S. Consulate. So if you are a Visa Waiver Program visitor who traveled by land to either Canada or Mexico for an onward flight, it is particularly important for you to register your timely departure if your green I-94W was not taken when you exited the U.S. If you fail to do so and you arrive at a U.S. port of entry seeking admission under the Visa Waiver Program without a visa, CBP Officers may order your immediate return to a foreign point of origin. If you are a VWP visitor and you left the U.S. by an air or sea carrier, you don't need to worry.

If your girlfriend want to follow the recommendations on that page and document her departure she may order a replacement copy of her I-94. See Form I-102. If she does need to document her departure and fails to do so in advance of her next travel, she may find herself having to document that she left as promised at the port of entry when she attempts to enter the U.S.

In terms of what documentation can help prove a departure date, see the list provided on the USCIS article page.