I think it just became assumed that adoptiin
took place - but theres so many loose ends!!
I know from friends experience that adoption
is a very long winded process -rightly to
safe guard children - and the child they
did adopt was not related to them so its
not exactly same situation .
You are right abt his attack on Gail. Also
round that time wasnt he on a rampage
of wilful/criminal damage on cars&
phone boxes etc and attacking Ken!
Apart from everything else hes done
and got away with over the years.
So yes it would nice if Callum did
develop love and affection for Max.
Of course the SWs could always be
true to form and ret-con things
so that Kylie & Callum had married
and not divorced - so Max not Davids
stepson -a bit far- fetched but no
more so than other stories they've
done