Kernrechtsfrage
Whether the procuring authority could request a missing reference after the tender deadline instead of excluding B.___.
Extrahierter Entscheid
Yes. Given the circumstances, the missing proof was a curable defect and the post-deadline supplementation did not unlawfully alter the offer.
Extrahierte Begründung
The court held that exclusion for minor formal defects would be overly formalistic. Supplementation is allowed if it does not affect the price/performance ratio or amount to a substantive change, and the omission here concerned a reference that was plausibly forgotten.