Left the US by plane. Still have my US Visa Waiver (I-94 A) [duplicate]

I regularly travel from Canada to the US by bus and get a US Visa Waiver attached to my passport, which I hand back to the Canadian customs officer when returning to Canada (by bus).

This time I entered the US by bus as usual, but left the country by airplane. When I tried to surrender the visa waiver to the Canadian customs officer upon arrival at the airport in Canada, he informed me he had never seen this before, and did not take the waiver out.

I understand that usually when flying to/from the US these records are handled through ESTA. Does that mean there is a valid record of me leaving the US, and that I can take out the waiver myself? Are there any additional steps I should be taking?

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How does U.S. immigration know when you leave?

By Plane or Cruise ship they know when you left and when you arrived by the ship's manifest and electronic information from security checks on your passport and boarding pass. They know this on everyone including citizens.

How do I get a certified copy of my I-94?

If you need a copy of your I-94 record of admission for verification of alien registration, immigration status or employment authorization, it can be obtained at www.cbp.gov/I94.

Does I-94 have Departure Record?

Form I-94 is the DHS Arrival/Departure Record issued to aliens who are admitted to the U.S., who are adjusting status while in the U.S. or extending their stay, among other things. A CBP officer gen- erally attaches the I-94 to the non-immigrant visi- tor's passport upon U.S. entry.

How long does it take to get a replacement I-94?

Instead, you will need to file a paper form with USCIS to request a replacement I-94. You must fill out Form I-102 ("Application for Replacement/Initial Nonimmigrant Arrival-Departure Document") and mail it to USCIS. If USCIS has your I-94 record, you should receive a copy of it within about two and a half months.

What is a Visa Overstay? Consequences and Solutions to Over staying a Visa

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