3-3 point invasion query 10

3-3 Invasion variation  

How would you answer this? I expected white to play at a following the joseki and letting his isolated stone in a very weak position.

Now if black answers b, the two white groups can be divided, but black stones are so weak that cutting the black stone at R5 (next to a) will let the white corner group expand.

It looks as if white Q2 was better than the joseki. How can white be punished (if possible)?

Gresil: I believe black is the party who has made the mistake: see here for an explanation for why black's hane at the head of two is unreasonable in this situation.