The main reason he was worried about recovery at that point was that the booster had splashed down into something like 20-foot waves. That's high enough to be

The main reason he was worried about recovery at that point was that the booster had splashed down into something like 20-foot waves. That's high enough to be real trouble for some of the recovery boats they wanted to have out there (which may be one reason why we haven't heard much about how it finally wound up). And it could also very well sink a rocket stage that wasn't built to handle this particular kind of buffeting, and is made to be pretty lightweight. As to longer term plans, it's not clear they will relaunch the first booster they get back, even if seawater exposure weren't an issue. More likely, they'll disassemble it, and see how the parts handled the stress of a full launch and re-entry, looking for wear that could endanger a second launch of the same booster. If there are any unpleasant surprises like that lurking, it's a lot cheaper to find out this way than in a launch with a payload at risk.