Answers
Since it is difficult to trust anybody in case of theft or disproportionate distributions, Glow should take deduction of the disproportionate distributions after informing police. If police is informed, then Bro will be prosecuted for illegal withdrawal and Glow can claim the amount as a deduction. Glow can claim the loss for the tax year in which he discovered it. The police case will also give a chance for Glow to recover the money from Bro which of course is more important than the tax on the money. If possible, efforts should be made to recover the money from Bro and then pay taxes.
Second option is for Glow to take deduction of theft loss after informing police. Police will help Glow to recover the amount from Bro. As a US tax court judge, the IRS can recover the tax from either Bro and Glow as Glow's contention is also right. Police will help IRS in recovering the taxes from Bro and help Glow in recovering his dues from Bro.
.