Actually lack of put buying in falling market isn't exactly a bullish sign. I play options sometimes, and lately the premiums on puts are just downright pathetic. You can buy some deep in the money puts with barely any premuims at all (20-40 cents), and thats 1-2 weeks before the expiration.
We should've seen at least some kind of a spike on this decline, and so far except for 5 day RSI being a little oversold, I didn't see a slightest sign of concern in any sentiment indicators.
Why do you think that is ? My guess is complacency.