When you want to add an assembly from a network UNC share using the command:
$scriptPath = Split-Path ($MyInvocation.MyCommand.Path) Add-Type -path \"$script
Instead of Add-Type you could:
Add-Type
[System.Reflection.Assembly]::UnsafeLoadFrom('\\uncpath\driver.dll')
It'll ignore some security settings and load the library but it's, well, unsafe ;).