A safety stop is just that - a safety stop, not an obligatory stop. If there
is not enough air for both to do the stop, then both simply ascend.

If you accidentally went above your NDL and had a required stop, that is
much differnt, and subject to endless variables.

If it was the first dive of the first day, you are probably fine, because
there is significant margin in the tables to start with. If it was dive 12
of a long live-aboard, then you could be in trouble, and this is where the
variables begin. I won't even try to list them.

It would be a better idea to start breathing oxygen prophylactically on the
boat than to attempt in-water recompression. If you did get DCS, you don't
want symptoms to start while under water...

Allow me finally to say that if you went OOA AND overstepped the limits, you
should be shot, or at the very least return your C-card ;-)

Bjorn