can blocked person reappear in my FB without permission?

[lauranikk]

I blocked someone from my friend´s list and suddenly without permission he started commenting again, can this be done?

[sewrobb]

Yes it's possible if your friend has his set to Friends of Friends or Public.

Blocking only affects profile to profile. It wont stop others posting through another profile.

[rjhfocus77]

no, if you've blocked this person, then this shouldn't be possible, blocked mean's the entire content of your profile is blocked to the person you've blocked

[Angeleyes]

No, this is not possible, once you block someone they cannot access your profile or comment on anything.