It's more likely that he moved his btc to 5 different addresses. If this person sold, btc would have come out of one address over a period of time. Then the bitcoins he sold would be circulated to other individuals.
A 5 wallet split to diversify his holdings seems more likely.
This seems to be the most likely case. It seems like it was all done at once, as if someone were moving coins to different wallets for storage. But this is exactly why it's very misleading to try to link # of addresses with # of people. You really can't tell.