One thing that puzzled me last night

Following a clash of heads between Papac and Trakys both trainers came onto the pitch, Pacac was eventually stretchered off while Trakys, following treatment left the pitch as required.

The Rangers sub was allowed on prior to play resuming but Trakys had to wait till play started before being allowed back on.

Surely in a situation like this either both should have been allowed on straight away or both should have to wait till play resumed.