In a word, Yes. Allow us to elaborate.
Suppose you purchase a set of Oracle licenses from your friendly Oracle sales rep. Is it possible that the licenses you purchased would put you out of compliance immediately? YES. Consider the following example scenarios: 
  • You purchase 2 Processors of Database Enterprise Edition with the intention of running it on a 2 processor server. Along with this, you also purchase 50 NUPs of Diagnostics Pack to run on the same server. You figure 50 NUPs will be sufficient since the minimum is 25 NUPs per processor, so 50 NUPs of Diagnostics Pack will be enough. Then your Oracle Sales rep may have overlooked this or forgotten to remind you of an important contractual detail: Options and Packs must match the Database licensing. So if the database is licensed by processors, you must license the Diagnostics Pack on processors too; NUPs cannot be applied. Your use of Diagnostics Pack is already non-compliant. To sum up, you can buy mismatched Database and Options/Packs license quantities and/or metrics. It will immediately put you out of compliance since Database and corresponding Options/Packs licenses must match metric type and quantities. The Oracle Sales rep will likely point out the mismatch, but mistakes happen.
  • Along the same lines, say you purchase processor licenses for a production server and NUP licenses for the corresponding DR server – this too will put you out of compliance since since DR servers must match production servers on metrics. Out of compliance again!
  • You buy E-Business Suite with the intention of making modifications to it (90%+ of EBS customers do so). However, you are not aware that making modifications to EBS requires you to separately license Database Enterprise Edition and Oracle Application Server Enterprise Edition. Again, you can buy EBS without DB and Application Server licenses, but will be out of compliance the moment you make modifications to EBS (who doesn’t?).
  • You buy a product but an insufficient quantity of its pre-requisite product(s). Though not very common, we have seen our fair share of this happening too. 

There are countless other scenarios like the above, arising due to other factors like virtualization, and shared storage, among others. The point is that technically, you can be sold licenses that immediately put you out of compliance. Why would this happen? Due to several factors, including:
  • Oracle Sales don’t always understand Oracle licensing themselves. This is not surprising, since Oracle licensing is very complicated and not always clearly documented. Mistakes can and do happen.
  • The customer did not properly or clearly convey their architectural details that would enable Oracle to sell the correct license sets. Alternatively, Oracle Sales may have failed to grasp the customer’s architectural details.
  • Sales personnel under pressure to close a deal. We all know how sales cycles work. It’s not uncommon for Sales personnel to “overlook” or fail to provide crucial licensing details to customer.
Finally, we arrive at the obvious question – who’s fault is it? Almost universally, it’s…. the customer’s. Oracle Sales and License Management Services (LMS) will always remind the customer that it’s the customer’s responsibility to understand the agreements they are signing – this includes understanding all the metrics, licensing rules, and just about every other detail (that is not always clearly documented). By signing the agreement, the customer has taken full responsibility. Of course, Oracle will be happy to sell additional licenses to correct the compliance gap.
Being knowledgable of licensing details and not leaving anything to chance (or up to your Sales rep) is the first step making sure you are not sold out of compliance. If in doubt, get expert, independent help.