It's all about the timeframe. Putin can point out that the rouble has gained over 12% against the USD since this morning. Sanctions have kickstarted Russia's economy.
It fell 19% today. The economy is going to contract even more sharply now. He can make no such claim unless he is to blatantly lie. But they can not mention it on the media, which is what they have been doing.
Hasn't he been doing this for quite a while ("no Russian soldiers in UA" and so forth). I was just making the point that it would be quite appropriate for Putin to frame the issue in such a manner ("What ruble collapse? The dollar has lost 12% since this morning.").