On the sequence from your quote:

This system was established by the 7th century in India, but was not yet in its modern form because the use of the digit zero had not yet been widely accepted. Instead of a zero sometimes the digits were marked with dots to indicate their significance, or a space was used as a placeholder. The first widely acknowledged use of zero was in 876.

Things were not very consistent at that time. AFAIK the most common was to leave empty spaces, but several people tried to cope with it by different methods. Also AFAIK, that dot was a mere typographic icon, to make the empty space clear, but it wasn't well accepted that you should actually put something there.