The 'banner' was most likely there for the photo op. company that takes pictures at the finish line(sometimes from a raised platform)so that the name appears in your finish line photo. So, '30 yards past the finish' would be useless. As one post suggested the logo could be added post picture (or just put a logo in the bottom corner of the photo). There was no doubt a business contract for this arrangement.
I hope RC recovers 100% and does not feel the need to sue. If he misses Boston, Chicago definitely owes him the appearance fee Boston would have paid the defending champion and the possible winners cheque amount for good measure. Next year they give him the normal returning champ fee, whether he runs or not, and all carries on as usual. I've never heard a bad thing about Pinakowski and am guessing that he will do what is right for all involved.