NFPA 13, 2013 version has additional provisions to support sprinkler piping from shared supports under 9.1. NFPA 13, 2010 version does NOT have these additional sections and is more general. Was it / is the intent of NFPA 13, 2010 version to prohibit the use of shared support structures? or Was this additional language in NFPA 13, 2013 version added for additional clarification?
My opinion is that you need to look at the code that is being enforced solely, in this case NFPA 13, 2010. You cannot look ahead and assume that the intent of new code sections is to prohibit design solutions in old versions of the code.