Marshall, who was recently unveiled as the new face of the NRL, as Stewart was in 2009,
escaped immediate sanction from the NRL on Monday pending his court appearance in Sydney on April 20. Manly has backed the decision but says it is inconsistent with the treatment of Stewart.
"In hindsight, in light of the NRL's most recent decisions in similar matters, the fact that Brett was suspended for four weeks and the club fined $100,000 would appear to be grossly unfair," Lowe said.
"The club doesn't take any issue with the recent decision of the NRL in the case of Benji Marshall. Allowing the legal process to take its course, without intervention, is the correct decision to take.
"The problem the Manly club and its supporters have is that the same support was not given to Brett Stewart."