For the person that you referred - what date was that order placed? If it was prior to May 19th you will not qualify for the Radio Flyer. I got that information directly from Tesla in an email I sent to them:
For referral rewards, Referrals received from March 16th-June 15th 2017 will count for Phase 8, and referrals received from May 19th-December 31st 2017 will count towards Phase 9 (and thus, show up in the app). Any referrals placed between May 19th and June 15th 2017 will count towards referral rewards for BOTH phases.