Surprised by home getting included in the deal (6,2)

'surprised' is the definition.
The answer and definition can be both related to competing as well as being past participle verbs.
Maybe they are linked in a way I don't understand?

'home getting included in the deal' is the wordplay.
'home getting' becomes 'thrown' (I can't justify this - if you can you should give a lot more credence to this answer).
'included' is an insertion indicator.
'the deal' indicates anagramming the letters (I've seen 'dealt' mean this).
'in' with letters rearranged gives 'ni'.
'thrown' going around 'ni' is 'THROWN IN'.

'by' is the link.

Can you help me to learn more?