I must admit I did read the whole article, but did he then go on to click any naughty links? If he simply looked up "knockers" then looked at DIY stores, then he has a case for unfair dismissal I assume.
I would have hoped even in this case the company would have looked at the whole trail, from sending the search term to the number and type of further links clicked.
Work policies are in place for a reason, they are to protect the company or organisation's reputation. Silly example, you work a well known company, surf a little bit of the naughty stuff during your lunch break. The owners of the naughty site then spot the IP, reverse lookup then decide to call up the company HR dept to report that one of their employees is looking up porn on the website and unless the company coughs up some money, they will take it to the papers. Bloody stupid example, but possible I suppose. I have worked in companies where employees have done something stupid, caused others from outside the company to make threats against other employees, Police are called in and the original employees are sacked, to ensure the company protects it's reputation and the safety of its existing employees.
Most companies are OK with a bit of personal surfing to online stores, eBay, even maybe a little Facebook if that's your bag, just to in the name of keeping employees happy and being fair, but looking up porn? If your company is stupid enough to not have a web filter at the gate, like Websense for example, then you need to keep your nose clean and use some common.