Are Plumbers contortionists?

This morning I discovered a pool of water under the sink in the utility room (again) which is coming from the inlet pipe for the washing machine. For some reason it works loose, but I cannot work out how to get a good grip on it to tighten it up. The inlet pipe is located directly behind the drain pipe from the sink and it is impossible to get more than a finger on each side to try to tighten it up. I cannot work out how the plumber fitted the tap there in the first place, he must be a contortionist or he fitted it before the sink and drain pipes were fitted.

This is not the first time I have discovered 'difficult to get at' plumbing, is it a master plan of the plumbing industry to locate pipes, taps and drains where only another plumber can fix it when it goes wrong? Anyway its tighter now, but the bowl stays underneath just in case it starts again.