Or alternatively, that the staff of the French-owned hotel would have cooled her down, cleaned her up, and given her the day off. DSK is a very good customer, you know. And the future Monsieur le Président! I'd bet some combination of those two theories is what enabled him to get away with past incidents.
The article stated he had seven phones. That's bizarre. Two phones — one for US and one for Europe — that I could believe. I keep an old Nokia GSM around for trips to Europe. I just charge up the SIM when I get there. But I also take my US CDMA phone along to use during departure from and arrival and to the US.
His status on this planet was second only to the President of the United States. He likely has several phone numbers: one for family, one for friends, one for work. Multiply this by two (the USA and Europe) and you are looking at six phones already. Perhaps he also grabbed a prepaid phone or two for affairs that better remain secret (one of them failed to remain secret, though.) This is particularly important if he receives SMS and email on those phones; you do not want to mix IMF business and personal messages, and often it's not even technically possible (one phone == one email account.)