That's "poor man's cloaking". Most people that genuinely care if it's Googlebot or not will verify it appropriately by doing a DNS lookup and a reverse DNS of t

That's "poor man's cloaking". Most people that genuinely care if it's Googlebot or not will verify it appropriately by doing a DNS lookup and a reverse DNS of that IP to ensure it's one of Google's IPs. 'Faking' the UA is much more likely to annoy site owners and end up with a permanent block.