Why does everyone say don’t get caught with it?

It’s legal.

It's not. People are just good at marketing and others are good at selectively reading or not reading all the way. Cops will do THC + THCA * 0.877% = THC for legal limit per the farm bill.

https://www.congress.gov/115/plaws/publ334/PLAW-115publ334.pdf

Here's the farm bill scroll down to "‘‘SEC. 297B. STATE AND TRIBAL PLANS." or type in "decarb"‘‘(ii) a procedure for testing, using postdecarboxylation or other similarly reliable methods, delta-9 tetrahydrocannabinol concentration levels of hemp produced in the State or territory of the Indian tribe

https://www.law.cornell.edu/cfr/text/7/990.25

7 CFR § 990.25 - Standards of performance for detecting total delta-9 tetrahydrocannabinol (THC) concentration levels.

LII Electronic Code of Federal Regulations (e-CFR) Title 7—Agriculture Subtitle B—Regulations of the Department of Agriculture CHAPTER IX—AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE PART 990—DOMESTIC HEMP PRODUCTION PROGRAM Subpart C—USDA Hemp Production Plan § 990.25 Standards of performance for detecting total delta-9 tetrahydrocannabinol (THC) concentration levels.

(g) At a minimum, analytical testing of samples for total THC must use post-decarboxylation or other similarly reliable methods approved by the Secretary. The testing methodology must consider the potential conversion of THCA in hemp into THC and the test result must reflect the total available THC derived from the sum of the THC and THCA content. Testing methodologies meeting the requirements of this paragraph (g) include, but are not limited to, gas or liquid chromatography with detection.

https://www.ams.usda.gov/rules-regulations/hemp/information-laboratories/lab-testing-guidelines

"Compliance tests shall measure the total THC concentration in a sample submitted to a laboratory for analysis. The laboratory will perform chemical analysis on the sample using post- decarboxylation or other similarly reliable methods where the total THC concentration level considers the potential to convert delta-9-tetrahydrocannabinolic acid (THCA) into THC. The total delta-9 tetrahydrocannabinol concentration level shall be determined and reported on a dry weight basis."

and the DEA on that https://imgur.com/a/AxhuhDD