Adding seemingly trivial things to code can sometimes throw off performance entirely, by disaligning cache tables and such. It's not always cheating.
That said, if this is a pure bug, it seems pretty pathetic. For one, it proves that the engine is not robust. For another, it probably means that someone spent hours upon hours tweaking the code with only the sunspider benchmark as test - analogous to over-fitting the training data. It's really tempting to do this, but it's also a common enough amateur mistake that Microsoft should have best practices to avoid it.
All this is speculative for now. Let's see what they say.
That said, if this is a pure bug, it seems pretty pathetic. For one, it proves that the engine is not robust. For another, it probably means that someone spent hours upon hours tweaking the code with only the sunspider benchmark as test - analogous to over-fitting the training data. It's really tempting to do this, but it's also a common enough amateur mistake that Microsoft should have best practices to avoid it.
All this is speculative for now. Let's see what they say.