Still does not explain why these tools do not function but apparently the "Delineate TIN Data Area" should be used instead? Seems that the work-flow to create and edit TIN surfaces has changed a lot; perhaps this is to accommodate greater flexibility in creating custom models?
I'm not able to replicate your result and was wondering if its possible that the TIN already had a clip feature defined. If not, would you mind uploading your data for me to test with?
I am also experiencing the same problem, that is; I am trying to use a multipatch feature as a matrix to alter a TIN. Any hints on how to work with this would be greately appreciated.