I understand it might look controversial from the moral perspective but there were no negotiated support promised. Also the Soviets were fully aware that UK is planning to fly the anti-Soviet government to Warsaw following the uprising. To postpone attack was a sort of real-politic. Legally based on the norms of foreign policy they did nothing wrong.
But it was clear that the Soviets did not want Poles to choose their post-war destiny.
That was a pretty impressive (if unpersuasive) rhetorical dance - got one for Katyn Forest as well?
These Vikings, apparently they are expanding to Moscow, again.