There is no ratified act of union that is the same passed by both countries parliaments. You can't pass an international treaty in one country even if as you say all the mps voted for it. This is a no, no. In normal cases, where things work out, this is a fact only a few people would know or care about but when things go wrong people start looking carefully at the contracts and and Somalia's paper work doesn't add up. And even if all Somaliland MPs voted for it, as you claim, they would have been 33 out 123 and their no vote wouldn't have swung the issue and the people of the north rejected the constitution.
You could say there never was a legal act of union. Something the AU fact finding mission also supports.
You could also say that, Somaliland post 1991 is the successor state to British Somaliland. So really it all comes down to interpretation. Now you have your view which is one way and some people have another view which is another way and you are entitled to your opinion.
