Swiss pairs. 2♣ showed hearts and another, at least an opening hand but less than a 16-count. The first double was not alerted. South asked before doubling himself, and was told that it was for takeout. North and South both thought the second double was for penalty (presumably it was alerted, although I didn't check). The final double was for penalty. 3♥x went 2 off.
The E-W convention card says they play Rubensohl after interference of 1NT, except after a natural 2♣ overcall where they play system on (dbl=Stayman). It says nothing further about the meaning of doubles after 1NT is overcalled. East said that he thought the double showed values. South said he would not have doubled 2♠ with that explanation. North said she pulled the double because she felt she didn't have a good enough hand for her 2♣ bid.
How would you rule?