He's on DT2, but that shouldn't really matter to use the Trust system correctly.
Next time I'll have to read the
fine print more carefully

If you find someone who has sent accurate trust actions and has no inaccurate/inappropriate trust actions, add them to your trust list. Inclusion in trust lists is a more a mark of useful contributions than your trust in them, though at least a little trust is necessary.
I'll have a second look at my trust list and make some changes where needed.
Thanks Loyce for the heads-up !