"Running programs" is easy. Getting correct answers, not so much. In the case of factoring 15, afaik, nobody has been able to execute Shor's algorithm faithfully -- instead, they simplify the factoring problem using knowledge of the answer. This isn't necessarily about Google -- last I looked, IBM holds the "factorization record" where they were either using a modified Grover's algorithm that incorporated knowledge of the factors. This isn't my area of expertise, but if it was, I'd be hugely embarrassed by the industry.
And then off in the corner, we've got D-Wave, who everybody loves to hate on, doing their own thing with an optimization-based approach to factoring which actually seems to work on (iirc) 10-ish bit semiprimes and zero foreknowledge.
