AITA for removing my coworker’s access after she kept changing our shared calendar?

I manage a shared project calendar. My coworker Dana repeatedly moved deadlines to make her tasks appear on time, saying the dates were internal estimates.

After warning her twice, I removed her editing access. That also prevented her from adding a client meeting, which the team missed. We lost a renewal opportunity.

Dana says I should have limited specific fields or told our manager before changing permissions. I say calendar integrity was already affecting everyone.

I knew her role required adding meetings. I removed full access because partial restrictions took longer to configure and because I wanted the consequence to be immediate.