If you are talking about the 1953 coup, I've never heard that description. Everything I've read says the UK, with some degree of US support, overthrew the government.
> And it's a little far fetched to call an armies call to take over the unstable situation a coup when the current head of the state is incapable to take any action because of a serious illness.
That's exactly a coup. The people who conduct coups - and other crimes and violations - always have a smooth justification. Russia is protecting Russians in Ukraine! Hitler needed some 'breathing room', etc.
If the head of state is incapable, then the next civilian in line can take over. No advanced democracy has ever needed the military's help for such a situation.