Yes, that's probably true, the problem is history tells us that hung parliaments don't bring PR.
What is likely to happen is Labour, without a sizeable majority will attempt to struggle on, either as the largest party, or with a slim majority. Thereby being in government but not in with the power to make real changes.
Next GE the Tory's will get back again and the 'merry-go-round' starts again, it's a political reality in the UK that no party that wins a sizeable majority under FPTP will ever vote for PR, it's the 'turkey's voting for Christmas' stuff! In any case there is then the problem of deciding what sort of PR system would we have?
One of the problems of us not having a written Constitution.