Your link to leszeks post is a dead link, just a fyi.
Unless you enabled the kubuntu backports ppa for 14.04 (trusty tahr) then you indeed would still be running KDE SC 4.13.x.
lsb_release -r only gives you the Netrunner Linux standard base release number (IE. Netrunner 14) and not KDE SC 4’s, to get the KDE plasma version number you would use kde-open -v instead.
Kubuntu Backports PPA btw. will be automatically activated with the update on 14.1 so if you update normally it will be activated by default.
Kinfocenter is not always reporting the correct KDE SC version. Clickin in Dolphin on Help -> About will show you most likely KDE SC 4.14.2.
As for muon just reinstall the muon package and muon discover if you like the more software center look a like tool. lsb_release -r should show 14.1 with the base-files package update from 2 days ago.