Is there a term for someone who takes a long time explaining simple things?

Is there a term for someone who takes a long time to explain simple things, but goes through the complicated ones very briefly?

We had a refresher course on a software we already use, the presenter took a long time to go over some basic forms that everyone already knew how to use, but explained the tricky stuff very briefly. At the end of the meeting the presenter got flooded with questions.

I've seen this before. Is there a word / term /phrase for this?

• He only explored the surface

• We only saw the tip of the iceberg

Solution 1:

He skirted over the complex subjects which everyone wanted to know about. Most of his time was spent saying very little at great length about basic subjects everyone already understood.