How to prevent autofs from mounting over specific directories?
You may be able to add something like
foo /-
to /etc/auto_home to prevent /home/foo from being mounted over the network. Make sure it comes before the +auto_home line (which asks Directory Services for mappings), so it will take precedence.
If that doesn't work, the only way to do it is to move your actual home directory somewhere else (by convention, /export/home) and configure auto_home to "mount" it from there.