Edit: or of course they could have sent a saliva sample to one of the genealogy sites, assuming they had enough to part with some, and it was in suitable condition to work with the site's test equipment.
That's unlikely without special arrangements. Have you ever done a 23andMe sample? The tube requires a lot of saliva. My understanding it's vastly more saliva than they need and the main reason is to make it impossible to surreptitiously collect enough saliva to genotype someone without their cooperation via 23andMe etc.
MyHeritage.com[1]:
> "The MyHeritage DNA test enables you to get unique matches to users who have only tested with MyHeritage, as well as matches with users who uploaded their results to MyHeritage from other providers. Thanks to MyHeritage’s wide international reach and availability in more than 40 languages, you will have a greater chance of being matched with relatives who live in other countries. You will also receive a comprehensive ethnicity analysis on MyHeritage, drawing from the largest pool of possible ethnicities in the industry."
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FamilyTreeDNA[2]:
> "If you or a family member have previously tested your autosomal DNA at 23andMe© or AncestryDNA™, you can transfer your results to Family Tree DNA by uploading your raw data file. After transferring your file, your autosomal data is uploaded to our database, one of the world’s largest genetic genealogy databases.
"When you transfer, for free, you will receive a list of your autosomal matches from our database and have access to our Family Finder – Matrix. The Matrix feature allows you to select and compare the autosomal DNA relationship between up to ten of your matches at one time."
Please note that you can only transfer the following file versions:
- 23andMe© V3
- 23andMe© V4
- AncestryDNA™ V1
- AncestryDNA™ V2
[1]: https://www.myheritage.com/dna (https://web.archive.org/web/20180423021411/https://www.myher...)[2] https://www.familytreedna.com/learn/imports/transfer-autosom... (https://web.archive.org/web/20170318130533/https://www.famil...)
Other services like Gedmatch, do the same thing.