Stelmane didn't die from a stroke, she was murdered and her hand chopped off at the Elfsong tavern as part of the string of Bhaal ritual murders with Orin's quest: notes, npc, baldur's mouth all collaborates this its part of the main quest; the 'stroke' was the cover story when the emperor latched onto her mind, the exact scene he shows you is described in Murder in Baldur's Gate, which happened before DR1479 over a decade before BG3, in theory, the emperor having a hold over Stelmane's mind and being a friend and associate could both be true. The 'enthrallment' the emperor had over Stelmane wasn't the usual enthralling where her mind would be blown out and rewritten to be a loyal servant, she was described as having her mind and will intact but restrained and suffered when she is actively resisting. Its' all speculation without more context and facts. Which is precisely the problem with the Emperor and much of the latter portion of the game lack of consistency and holes in story
I got the part about her death mixed up. Doesn't really change the overall point though. He lied about his relationship with Stelmane. I don't think being put in a coma and getting turned into a mind controlled thrall for a decade could constitute a friendship by any stretch of the imagination just because the Emperor may or may not have gotten sentimental about his favourite pet. That's some very skewed thinking.
