If he wants her back after being dumped 2 years ago I think that he really likes her, otherwise he wouldn't have kept contact or try to reunite. 2 years seems a really long time for someone to seek revenge. Your friend though has to really think if she wants to get back with him and how the relationship was because if the relationship was good I'll doubt it if your friend will look for someone else. If she is sure she can give a second chance to the relationship but she should take things really slow. If she wants to be sure of the man's intentions she should pay close attention on how he approaches her.