We consider bubble collisions in single scalar field theories with multiple
vacua. Recent work has argued that at sufficiently high impact velocities,
collisions between such bubble vacua are governed by 'free passage' dynamics in
which field interactions can be ignored during the collision, providing a
systematic process for populating local minima without quantum nucleation. We
focus on the time period that follows the bubble collision and provide evidence
that, for certain potentials, interactions can drive significant deviations
from the free-passage bubble profile, thwarting the production of bubbles with
different field values.Comment: 21pages, 8 figures, Revised version modified to include
Acknowledgements sectio