Whats the call ?

[debeau]

I am 1st base umpire .
Runner at first and batter hits a high ball to centre field which is caught .
Runner has lead off and is foot tripped on purpose and gets up and runs through 2nd and is thrown out at 3rd .
I call dead ball , obstruction safe on third and eject the 1st baseman for unsportsmanlike behaviour .
The coach comes on and I give him my explanation , which he accepts.
He then appeals for the runner not tagging up .
I pass this to my plate umpire and he says no he didnt and returns the runner to 1st ( Also said I was wrong in the ejection privatly between us .)
The plate umpire is very senior to me and in the past has made it clear that his word is final , but I stick my neck out and between us two only say I believe the runner should be given out .
ISF interpretation and rulings .