Heroic raid lockouts and different groups?

[Netherspark]

If for example I clear half a raid on 25 heroic, then the next day join another raid with all different people but with the exact same progress, also in 25 heroic, can I kill the remaining bosses with them?

I seem to remember heroic lockouts being weird, and I vaguely remember hearing something that would prevent this (as in I can't enter a raid with a different lockout, even if it's identical to my own)?

So basically, if I get saved with one group, can I join a different group who are also saved?

[Stumpurin]

Nope, won't work. Only works for normal modes.

However, if you've only done normal bosses, you can join a heroic lockout just fine.