Can you disable solid behaviour for the object when you detect that it's actually crushing the player?
You can set a boolean instance variable for the player perhaps, and when they're being "crushed" then disable solid on the crusher - and use other events to control the position/size of the player to control the crush "mechanic".
I guess it's a little difficult to make a suggestion without seeing how your current mechanics are working, and what you're wanting to achieve cosmetically.
~Sol