Blog Single post code deletion = Syntax error. How to restore?

I was adding a tweet button code to the single post (single.php) template in appearances via the editor and I have now mistakenly have deleted a some text which is now showing the below error when I click on the post to read more. The blog theme itself is custom and I don’t have the code backup on my computer as my web guy went awol after design. My site is ww.besosconcierge/com/blog.

Parse error: syntax error, unexpected ‘?’ in /home/besoscon/public_html/wp-content/themes/Besos/single.php on line 73

Do you know how I can restore the single post template to how it was this afternoon. And in turn a more easy way to add a tweet post button rather than touch codes I have no right to touch since I don’t know what the heck I am doing. LOL.

Many Thanks in advance for your help.