I can see this going both ways.
You already had 264 ilvl pants, and you need rolled for an item, that upgrades weaker 251 ilvl pants into 264 ilvl pants (equal to your current), basically you could say extra step to your your own preferred play style, not an upgrade. Not really an upgrade on ilvl regard, and I believe ilvl is usually the factor what determines if item is better on RDF/PUG scene. Min-maxing is secondary. So depending on Warmane's stance on min-maxing with same ilvl items, and who reads and how he interprets the ticket, and how in general they view the situation, you may or may not end up banned. Don't be too surprised if you do.
Technically you just prevented somebody from obtaining direct upgrade item (251 -> 264), while you switched to another 264 ilvl (264 -> 251 -> 264)..
Was it really stated a free roll, or was it more of a MS roll?
Raid's average GS, and their gear doesn't matter. And note that some may have changed their MS to roll for their OS, which is fine and allowed most raids. So people needing for "OS" may have been OK'd in a sense.