This is a big leap to make from the available evidence. Mission targets change all the time. It's a very fluid situation with many unknowns, so I don't find it at all surprising. I think calling foul play is premature to say the least.
Until 12 November the FAQ [1] stated:
During the first week – the minimum mission target – a first run of the most important scientific measurements will be completed. During this phase the lander can operate on primary battery power, should this be necessary. In a second phase that is meant to last up to three months, a secondary set of observations will be conducted, using backup batteries that will be recharged by the energy from the solar cells on the lander. However, no one knows precisely how long the lander will survive on the comet.
Editing to omit the minimum mission target on 12 November [2] indicates something was already wrong at that stage, which would presumably relate to the two batteries that were to power the lander over more than a week, but no public announcement of any issue like that was made. So we should instead assume the batteries were fully operational.
Instead we have ESA announcements and news articles asserting that the reason for the very short period of operation was a lack of solar power, but solar was never planned to be required for over a week at least.
It seems obvious that they had a battery failure. That would not be surprising, but why not openly announce it?
[1] https://web.archive.org/web/20140805030451/http://www.esa.in...
[2] https://web.archive.org/web/20141112043243/http://www.esa.in...
Also, there are probably N things that didn't happen as they thought it did. It is better to mention the K important things (K << N), than the N unimportant things that they got wrong.
If Philae, for example, didn't land on the comet at all, then they would have announced something like this: "Philae took a drive-by of the comet 67 p, and has done in-air experiments that would be valuable for us".