I'm not a fiscal specialist but I know a thing or two about the topic and I think your description is pretty accurate.

It can get sleazier since with enough tax paying clout and and a decent payroll (ie jobs thank can be relocated) a company can still cut a deal after being caught paying insufficient taxes.  Once the auditor has told you how much back taxes you owe, the haggling can begin in earnest and there's now way in hell the big players ante up the full amount penalty and all.