Well, strictly speaking, you did violate section 3 and possibly 15.
3. Communications Solely With Google. You agree to direct to Google, and not to any advertiser, any communication regarding any Ad(s) or Link(s) displayed in connection with Your Site(s).
By making this topic, you started a discussion about the Google Ads with someone else than Google. That's technically a violation of the terms of use, although I've seen many sites make a topic on their forum about the ads, so I don't think that this would be the cause.
15. Google Rights. You acknowledge that Google owns all right, title and interest, including without limitation all Intellectual Property Rights (as defined below), in and to the Program (including Google's ad serving technology, search technology, referral technology, and Brand Features, and excluding items licensed by Google from third parties), and that You will not acquire any right, title, or interest in or to the Program except as expressly set forth in this Agreement. You will not modify, adapt, translate, prepare derivative works from, decompile, reverse engineer, disassemble or otherwise attempt to derive source code from any Google services, software, or documentation, or create or attempt to create a substitute or similar service or product through use of or access to the Program or proprietary information related thereto. You will not remove, obscure, or alter Google's copyright notice, Brand Features, or other proprietary rights notices affixed to or contained within any Google services, software, or documentation (including without limitation the display of Google’s Brand Features with Ads, Links, Search Boxes, Search Results, and/or Search Buttons, as applicable). "Intellectual Property Rights" means any and all rights existing from time to time under patent law, copyright law, semiconductor chip protection law, moral rights law, trade secret law, trademark law, unfair competition law, publicity rights law, privacy rights law, and any and all other proprietary rights, as well as, any and all applications, renewals, extensions, restorations and re-instatements thereof, now or hereafter in force and effect worldwide.
By trying to download the Javascript, I believe they might have thought you were trying to get it for the purpose of modifying it ("You will not modify, adapt, translate, prepare derivative works from, decompile, reverse engineer, disassemble or otherwise attempt to derive source code from any Google services, software, or documentation, or create or attempt to create a substitute or similar service or product through use of or access to the Program or proprietary information related thereto."). Just downloading it alone might constitute "attempting to derive the source code of".
All in all, though, I still find it very strange and wrong that they terminated your account.