The Vてしまった of standard Japanese, when used as an expression of completion and/or regret, can become Vてしもた or Vても(う)た in Kansai-ben. As the have very much the same feel, the word choice is left to the speaker.
Common uses:
Grammar elements:
Kansai vs. Standard:
| Standard | Vてしまった |
|---|---|
| Kansai-ben | Vてしもた Vても(う)た |
Formation:
Formation from standard:
| Standard | 行って しまった |
|---|---|
| Kansai-ben | 行って しもた 行って も(う)た |
Example:
| Standard | あー、おさら割ってしまった。 |
|---|---|
| Kansai-ben | あー、おさら割ってしもた。 |
| English | Ack! I broke a plate. |

Commentary:
The function of Vてもうた
Vてもうた has another function that expresses receiving a favor (see: Vてもろた/Vてもうた). Please compare the different very different meaning and tone of the two: