screenshot below shows splendidly how #MediaWiki has improved its support for languages like Arabic and Hebrew. The sidebar is to the right, the labels used for the image are in Arabic and the descriptions are in the direction of the language indicated.
As you can see, the "Summary" is a text in English and it is displayed in the wrong direction for English. This is probably the consequence of the software not knowing that this text is in English.
This is clearly a bug and it needs to be reported. The obvious way is to report this in Bugzilla. A bug reported in Bugzilla ensures that there is a record of this issue. It is likely that more issues like this bug exist where support for the use of RTL languages breaks.
In the Localisation team we are exploring the known RTL bugs. This is the best time to experiment with the combination or RTL languages and LTR languages because at this time we are extremely receptive and are able to resolve them relatively quickly.