inconsistent results given by GitHub API

what is given by requests.get("https://api.github.com/repos/{}/{}/branches".format(fork.owner.login,fork.name)) is not consitent with what is shown in the online network view

see repository openp2pdesign/Github-Social-Network-Analysis, branch ExtModuleTUB:

ends with commit 1525b5df9075766375b559a9b9e23305563a72e3 according to this request
ends with commit f6fc967ca904a2fed57c77b6c2d599aa11302e48 according to the web interface

jbon / Github-Social-Network-Analysis

inconsistent results given by GitHub API #12