It means he didn't use his full power and Luffy would have needed to do more. Not that hard to understand.
Luffy failed to remove him as a threat. That is fact. If he did Zoro wouldn't be fighting him.
That don't really matter since a day has gone by and Lucci would have woken back up because he is a Zoan .
In fact they did remove them as threats and even had them in sea stone cuffs .
After everything done they not put them back in season cuffs or even a bubble after the team up was done ( you can see this is Oda making all SH act like luffy which is dumb )
So now we have luffy fighting Kizaru one place and Zoro fighting lucci when lucci should not even be free.
I really dislike when Oda make the smart SH stupid like this .