When they say "peninsular Spanish" are referring to Spanish from Spain.
The definitions I found were not very clear as being specifically that type of Spanish, but I found this online translated as:
Bolazo
1. Violent blow with a bowl. (m)
2. (Cono Sur) silly remark, piece of nonsense (disparate); false news; fib, lie; mistake, error. (m)
Mandarse un bolazo -> to put one's foot in it
