A spat between the Balancer and STA team following the $500,000 hack suggests that the DeFi protocol was aware of the weakness.
Source: https://cointelegraph.com/news/defi-protocol-balancer-hacked-through-exploit-it-seemingly-knew-about
DeFi Protocol Balancer Hacked Through Exploit It Seemingly Knew About
June 29, 2020
CoinTelegraph