That's an excellent question... and one we'll likely never know the answer to. At best we can say, maybe, but likely not.

There's a number of accounts about how many people spent some time in the water. Peter Engberg in Titanica! estimated some 44-48 passengers and crew actually spent time in the water, and found some 79 accounts that say that they spent some time in the water. Virtually every account disagrees with every other account. For example Collapsible Lifeboat A contained 11, 12, 13, 14, 20, or 21 people depending on which first person account you read.

A majority of accounts of people in the water involve Collapsible Lifeboat B which went into the water empty and upside down when it was dropped. The 25-35 men pulled from it account for the majority of the people "pulled from the water." Most of these were people who jumped into the water specifically to climb aboard the overturned lifeboat. Collapsible Lifeboat A contained people from the water, but the total number is unknown. Outside of these, Lifeboat 4 pulled six survivors directly from the water, Lifeboat 14 pulled two or three survivors from the water, and Collapsible D pulled one from the water.

The best chance of someone who may have ridden the stern down would seem to be Robert Williams Daniel. There was a surviving crew member, Patrick Dillion, who said he saw Daniel leap from the stern just before it submerged. Daniel himself gave conflicting stories alternatively saying he leapt from the side into the water or that he jumped onto the overturned Collapsible B. But he's also mentioned by name as having boarded Lifeboat 3 with several first class ladies. So he has four different accounts, two of which were given by him, and only one of which involves the stern.

His story highlights the problem with many of the first person accounts. They are are terribly muddled and conflicting. Many of the people giving the accounts were confused and in shock. Virtually no one's account survives without conflicting with someone else's account. And there is a lot of motivation to be seen (especially among the men) as being plucked from the water, rather than taking a place in a lifeboat (that might otherwise have gone to a woman).

For details of the various accounts Judith Geller's Titanic: Women and Children First is an excellent resource.