Robert M. Gary wrote:

Are you able to cite the specific federal law that indicates airmen
have implied consent to law enforcement taking bodily specimens?

Looks like maybe 14CFR 91.17:

(a) No person may act or attempt to act as a crewmember of a civil
aircraft—
(2) While under the influence of alcohol;
....
(c) A crewmember shall do the following:
(1) On request of a law enforcement officer, submit to a test to
indicate the alcohol concentration in the blood or breath, when—

(i) The law enforcement officer is authorized under State or local law
to conduct the test or to have the test conducted; and

(ii) The law enforcement officer is requesting submission to the test to
investigate a suspected violation of State or local law governing the
same or substantially similar conduct prohibited by paragraph (a)(1),
(a)(2), or (a)(4) of this section.

....
(d) Whenever the Administrator has a reasonable basis to believe that
a person may have violated paragraph (a)(3) of this section, that person
shall, upon request by the Administrator, furnish the Administrator, or
authorize any clinic, hospital, doctor, or other person to release to
the Administrator, the results of each test taken within 4 hours after
acting or attempting to act as a crewmember that indicates the presence
of any drugs in the body.

(e) Any test information obtained by the Administrator under paragraph
(c) or (d) of this section may be evaluated in determining a person's
qualifications for any airman certificate or possible violations of this
chapter and may be used as evidence in any legal proceeding under
section 602, 609, or 901 of the Federal Aviation Act of 1958.