The empty tomb was verifiable: women as witnesses (embarrassing to early church = authentic), the women are named (eyewitness identification per Bauckham), Roman guards monitored it

Multiple lines of evidence: (1) If you have a living, breathing risen Jesus, the right tomb is not even strictly necessary — you have the living evidence. (2) You can check multiple tombs. (3) Women were the primary witnesses — embarrassing in first-century culture, suggesting historical authenticity. (4) Mark names the specific women because (per Bauckham's Jesus and the Eyewitnesses) named individuals are the eyewitnesses behind the account and were accessible to original readers. (5) Matthew records guards were sent to the tomb, meaning multiple parties were monitoring it. (6) Practically: identifying a crucifixion victim with unbroken legs among three crucified that day is straightforward.