Detailed description: Had 2 points into Summon Thorn Totem as my Specialization. 1 point into Torrent of Thorns and 1 point into Forested Expanse. Despecialized and went back and only recieved 1 skill point as opposed to both and when I put the point back into Torrent of Thorns it gave me Forested Expanse despite the fact there was no point currently in it and does stack with additional points put into it.
What were you doing at the time? Re-Specializing Skills.
How consistently does this happen? Seems to permanently allocate a point into Forested Expanse.
When you say it gave you Forested Expanse, was it 1/4, 2/4, 3/4, or 4/4?
How many charges of Summon Thorn Totem do you have? By default, you should have two. Forested Expanse increases this up to a maximum of six. Is it possible that you expected it to only have one charge by default, and you assumed the second charge was a bug?