The case for a DQ is absolutely there. The committee used rule 33 to make an exception for to a mandatory DQ.
It was clearly a judgement call. It was within the rules to make an exception for Tiger in this case, but absolutely not mandatory.
What you say is technically correct, but you miss one big point about rule 33; it was made for precisely this situation. Therefore, it compelled the committee to use the rule when the very situation it was designed for comes up, even though, as you say, technically a DQ was avalable too.
How can you possibly disqualify a golfer who relies on your judgment as a rules official regarding a questionable drop when you determine that the drop was legal and you allowed the golfer to submit the signed scorecard without a penalty?
You have given him the approval for his scorecard..........Then the next day you want to DQ him for submitting a bad scorecard AFTER you have determined that he should have been assessed a 2 stroke penalty???????
That just f'n nuts..........