"Rather than a panacea," Creese added, "open source can create unforeseen risks of lock-in and incompatibilities across increasingly integrated systems. As the links between different public service organisations become more crucial, incompatibility creates all manner of problems."
Isn't that the wrong way around?
Closed-source software like Microsoft produces is what creates risks of lock-in. They deliberately make their software tightly integrated, to increase that lock-in.
Open-source generally follows open standards, and can be modified/forked/replaced if needed.
Links between different organisations require open, well-documented standards for APIs and file formats. Allowing much more flexibility in system choice, and no need to "increasingly integrate" everything into one monolithic nightmare.
By all means allow public sector organisations use Microsoft, but require that they use open document formats. And ban the use of Excel completely!!