Strange Encounter with FamilySearch Family Tree Merge Function

I had the strangest thing I have yet seen happen on FamilySearch.org's Family Tree program. I was helping patrons at the Brigham Young University (BYU) Family History Library and had the same thing happen twice in one night. In each case, there was an obvious duplicate. Here are the two duplicate individuals from Family Tree:

• Pehr Svensson LHTY-BXS
• Pehr Svensson 9HHP-INQ

When I put in the first number, I got this individual's detail page.

You can see the ID number just below the name marked in yellow.

The second Pehr Svensson came from a printed ordinance card. When I tried to merge the two individuals using the second ID number, I got a completely different individual. First, the search for duplicates of the LHTY-BXS person did not find any. Then I searched by number and this is what happened. This is the search screen showing the two duplicate individual's by ID number:

When I clicked on the Continue button, this what happened:

The ID number that was on the printed ordinance card came up as Rosa Contreras Sanchez with an entirely different ID number.

This happened to two different patrons, both with obvious duplicates. Now, I am used to the merge function not working but never quite this strangely.The problem is that I cannot imagine any set of circumstances that would produce this error, especially twice in one evening.