I doubt it. There are many things that could cause patchyness, if the client has not exfoliated correctly before the tan, if they have not been moisturising after the tan, some areas just fade quicker than others and this can be caused by things like purfume and oily products put on the skin or excessive washing.
There are many reasons that tans go patchy and most of them are the clients responsibility. It could be the solution your using but if this is the first time your getting the issue then it is more likely to be a client issue than something you did or didn't do.