I just noticed that on Precise it's short_open_tag = On in /etc/php5/cgi/php.ini, while on Trusty it's short_open_tag = Off. This affects inter alia the admin web service that uses <? instead of <?php.
Web service is running now on Trusty:
tools.admin@tools-bastion-01:~$ cat .bigbrotherrc jstart -N toolhistory -mem 350M /data/project/admin/bin/toolhistory webservice --release trusty tools.admin@tools-bastion-01:~$