Complex sentence: A link to his comments was tweeted on the SFWA Authors Twitter feed, and he was investigated by the SFWA Board, who subsequently voted to expel him from the organization over his use of the promotional SFWA Twitter feed in an manner that allegedly violated organization guidelines.
Split into simpler sentences: A link to his comments was tweeted on the SFWA Authors Twitter feed. He was then investigated by the SFWA Board, who subsequently voted to expel him from the organization over his use of the promotional SFWA Twitter feed in an manner that allegedly violated organization guidelines.