Has Google Pinyin been stolen from a competitor?

A debate is emerging on the internet whether Google has for its newly released pinyin input system stolen the vocabulary of its competitor Sogou. When the US search engine would have committed such a gross infringement of the intellectual property of a competitor, even though it would have been done by local staff, that would put the company in a difficult position.
There are two different takes up to now. Yee and others point at awkward similar mistakes Google seems to have copied from the vocabulary of Sogou. The fact that Google has failed to respond to the accusations is already seen as an admission of guild.

China Web2.0 Review is an authority here and writes:

My take is that further discussion on this similarity case is not necessary. If Google really infringes Sogou’s intellectual property rights, they would sue Google. Is it possible that they all licensed vocabulary library from the same source? You will never know it.

I tend to disagree with both at this stage. The pinyin system seem to be much more than a vocabulary and you would have to compare more than only the vocabulary to substantiate the accusation - although Google does seem to have a problem here.
The fact that Google did not react at all is of course not good, but if they would have denied guild after the first rumors would have emerged, you would know they would not take the accusation serious at all. Google needs to have a thorough internal investigation, and they could have told us that.
I also do not agree with the argument that because Sogou has not started a court case yet, there is probably no case. Also Sogou needs to investigate the case and the systems is only out. Preparing a court case takes a long time and does not yet indicate that Sogou has already taken a position here.