If filling out the source code request form via Google Forms and/or accessing the download link via Google Drive requires the requester to run non-free (or at least non-GPLv2) JavaScript, then maybe it is in violation of section 6 of the GPLv2 ("You may not impose any further restrictions on the recipients' exercise of the rights granted herein") since the requester is then required to accept an entirely different set of licensing terms and conditions.
If filling out the source code request form via Google Forms and/or accessing the download link via Google Drive requires the requester to run non-free (or at least non-GPLv2) JavaScript, then maybe it is in violation of section 6 of the GPLv2 ("You may not impose any further restrictions on the recipients' exercise of the rights granted herein") since the requester is then required to accept an entirely different set of licensing terms and conditions.