Seen this a few times, where Sourcetree doesn't refresh. Restart sorts it out usually. This time however, a sed.exe.stackdump file was showing as a new file in my project directory. This may or may not be related to the first issue.

0 [main] sed 5944 open_stackdumpfile: Dumping stack trace to sed.exe.stackdump
MSYS-1.0.12 Build:2011-07-20 17:52
Exception: STATUS_ACCESS_VIOLATION at eip=00000000
eax=00000000 ebx=00000001 ecx=00000000 edx=00000000 esi=6809A16C edi=6809A174
ebp=0022FE88 esp=0022FE6C program=C:\Users\mgillespie\AppData\Local\Atlassian\SourceTree\git_local\bin\sed.exe
cs=001B ds=0023 es=0023 fs=003B gs=0000 ss=0023
Stack trace:
Frame Function Args
End of stack trace