Attraction is a tricky thing. Our unconcious mind selects or rejects partners through our point system. We usually say, "I know if I like someone or not"... It is there or not... And usually our "attraction radar" is not very correct. Especially if you have a history of selecting people who are not good for you, you will continue that pattern. Sometimes the person seems opposite of our partner but 3-4 months later when their true self is revealed you will find that you selected an partner with the same issues.
This recently happened to me, I ended my marriage mainly because of my husband's unreliability and emotional detachment. Right after I started talking to a high school friend after 25 years. This is the person who brings me to the forum. He was open, reliable, confessing his emotions openly... After 3-4 months though, his PTSD triggers started getting in the way. He was distant, dissappeared for weeks etc... Shortly, I again was attracted to an emotionally unavailable person. These days I am questioning if I am also emotionally available since I attract this quality. Again I liked him very much, I can say I fell in love
with him. To this day I am not sure if he just didn't like me after "getting" me or if his PTSD caused him to push me away. One way or the other though I again ended up in a similar historical pattern.
Shortly, you being not ready for a relationship after an incident is something serious to consider. However, if this friend of yours is kind, reliable and genuinely interested in you, I would try to date him. Changing patterns and dating people who you are not "attracted" to initially teaches us a lot about ourselves, especially if we know they would be good for us. Is he someone who you would be happy if he dated your best friend? if so, I would give him a chance or several chances. True love grows with time, compared to infatuation which is fueled by attraction.
Good luck...