I have very few problems with Double Shock, and this is just BARELY one, but it seems to me that Lisa Chambers goes from being easy-going around Columbo to being upset by him very quickly, especially for someone who's innocent.
Of course, Columbo later tells that to Hathaway, which gives him the idea of scaring her into giving him her copy of the will. Is that the main reason for having her get upset with Columbo (so it will lead to that, I mean), or am I always missing another one?