As far as I can see there is no real difference in this context. Normally however fall means to collapse whereas come means to move towards.

In those two sentences, the use of the word "fell" and "came" basically means the same thing. However, those two words in general both have two different meanings. The word "fell" is implying a harsh action for going a certain direction. For example I would say "I fell off my chair" not "I came off my chair". Also people use "I am falling in love with you" not "I am coming in love with you" the word "come" imply's you are going a certain way or approaching something. For example "Jessica came into the kitchen" or "Jessica is coming into the kitchen". Hope this helped a little!