That's very perceptive.
As I remember, Trump made an appearance shortly after the alleged phone call. What did he say? Something like: "Sorry for the delay... complicated business".
At the time, I wondered what was going on behind the scenes. It makes sense that someone with a rational demeanor -- perhaps even Bill Clinton himself -- called Trump and said: "Hillary is indisposed at the moment, but she offers her congratulations, and she will speak tomorrow."
That suggested to me that the call was abrupt and reflected a lot of embarrassment on the other end from someone who wasn't expecting to ever be in a position to make a call like that.