Can you explain what you mean by this? I wouldn't expect them to treat it differently, as I always think of CR as fair and un-biased.
I think they try to be pretty fair. But I think like many others, they didn't understand the plug-in market at first, and I think some of their past coverage was not very good.
Simple example: They don't rate 2-seater sports cars primarily on passenger or hauling capacity - they will note it is low, but still give the car good ratings if it does what it's designed for. They don't rate pickup trucks primarily on fuel economy - they will note it is low, but the truck still gets good ratings if it does what it designed for.
But many of their reviews of BEVs have stated that they don't recommend the car because the range is low. But just like Miata owners typically have another car in the family if they need to take 3 people to lunch, short-range BEV owners typically still have a gas car in the family if they need to drive cross-country. BEV owner satisfaction is extremely high; they just didn't understand how they are used.
They have done similar things with PHEVs, glossing over the differences between serial and parallel types, and not understanding how driving & charging patterns affect how often you are in electric mode.
Also, they have made the common error of assuming that it's all about cost savings - and compared a nice BEV to a very cheap gas car, left out some of the incentives and long-term savings (I sent them mail pointing some of that out; they thanked me but never made a correction), and then concluded the cheap gas car was a better deal even though the BEV was quicker, smoother, quieter, cleaner. They didn't even MENTION any of those benefits; a terrible disservice to readers that have not driven a BEV. I never see CR comparing a BMW 3-series to a Toyota Yaris and deciding the Yaris is better because it's cheaper.
These are all older examples; I assume they are getting better...I think the last thing I read from them was pretty good.