Relevant rules:
Starting with the attacker, each player alternates resolving one of their successful hits. They repeat this process until one operative in that combat is incapacitated...
Use this Tactical Ploy when a ready friendly GREY KNIGHT operative is incapacitated. That operative is not removed from the killzone until the end of your next activation...
In the Fight action, the players repeat the process of alternating hit resolutions until one of the participants is incapacitated or they run out of attacks. OIDDDE triggers when your operative is incapacitated, and just stops you from removing the model - it doesn't stop the model from being incapacitated.
This means that the Marine is not removed, but both players will need to stop repeating the hit allocation process. So no, you cannot just keep resolving the rest of your hits as Strikes.
If you were to then activate the Marine and perform a Fight action, you are permitted to resolve one hit each, but are not permitted to repeat the resolution process because one of the participants is incapacitated.
Note that the operative is removed at the end of
your next activation, not necessarily
that operative's next activation. If you were to activate some other operative instead, then the incapacitated Marine would be removed when you're done. You can't save that Marine's activation for later.
Edit: also,
CB p68:
When an operative is incapacitated, it is removed from the killzone...If an operative is incapacitated during a fight sequence, any remaining hits are discarded and not resolved.
This confirms that the remaining hits you have cannot be turned into Strikes. OIDDDE only stops you from removing the operative; they are still incapacitated.