A liability by definition only exists in relation to a prior obligation. Damages relatd to prior infringement fit this definition.
Paying 5% of what GOOG will pay in the future for future ongoing use of the patents is NOT a liability yet as no event has arisen yet to create any liability whatsoever.
Unless the parties simply did a piss poor job at crafting the agreement or the PR or the 8-K, if they intended for the cap to apply to future royalty payments, then they would have (or at least should have, anyways, based upon basic "Drafting A Contract 101" principles) used the language to include reference that the cap also applies to MSFT's FUTURE obligations.
In business, all parties, especially lawyers (who I presume had a hand in drafting this agreement), understand that the word "liability" has a very specific meaning and time horizon w/respect to the events/amounts being held "liable for". If the agreement was intended to apply the cap to ALL future liabilities, then it should have stated as such; otherwise, a very strong argument can be made that this cap on "MSFT's total liabilties" applies only to exactly what a liability is -- an amount owed in relation to consideration PREVIOUSLY received.
So, in looking at the actual text of the PR/8-K, the context of when and where the words "limitation on MSFT's total liability" appear is after the discussion re: future royalties.
BUT, at the end of the day, discussing MSFT's settlement is nothing more than an intellectual exercise for me. As stated previously, I didn't invest in VRNG for MSFT and anything MSFT has to offer is immaterial regardless of how GOOG shakes out.