I will have pretty similar views as Martin have. Once you have moved the request then its not possible to roll back the changes.
Your BASIS team must be taking the backup of it so they need to restore to the last backup point that means all your changes including data will be waived off that happened after that point.
I do not think for one code they would attempt to do this.Its costly affair indeed.
Note:I am not sure about BW 7.3 and above systems as i have not worked on them.They have some version management concept but do not know if that will be applicable in your case.
Regards,
AL