Oh, that's fake isn't it?

The portion of private key they show isn't possible:

Here is the very last address PK:
5Km2kuu7vtFDPpxywn4u3NLpbr5jKpTB3jsuDU2KYEqetqj84qw

Here is the supposed collision PK:
5Km2kuu7vtFDPpxywn4u3NLpbr5jKpTB3jsuDVwj9

5Km2kuu7vtFDPpxywn4u3NLpbr5jKpTB3jsuDU2KYEqetqj84qw
5Km2kuu7vtFDPpxywn4u3NLpbr5jKpTB3jsuDVwj9...

How can a V come after a U if it's the last PK?

Thanks,
Jude